what is the significance of photosynthesis class 10

Download the Learning Outcomes App Today

Share this article

Table of Contents

Latest updates.

1 Million Means: 1 Million in Rupees, Lakhs and Crores

Ways To Improve Learning Outcomes: Learn Tips & Tricks

The Three States of Matter: Solids, Liquids, and Gases

Types of Motion: Introduction, Parameters, Examples

Understanding Frequency Polygon: Detailed Explanation

Uses of Silica Gel in Packaging?

Visual Learning Style for Students: Pros and Cons

Air Pollution: Know the Causes, Effects & More

Sexual Reproduction in Flowering Plants

Integers Introduction: Check Detailed Explanation

Tag cloud :.

• entrance exams
• engineering
• ssc cgl 2024
• Written By Priyanka Srivastava
• Last Modified 22-06-2023

Significance of Photosynthesis: Definition, Products, Diagram

Significance of Photosynthesis:  At least half of the oxygen generated on Earth originates from the ocean via phytoplankton photosynthesis, with the other half produced on land through photosynthesis by trees, shrubs, grasses, and other plants. Photosynthesis produces oxygen, which is released into the atmosphere through stomata, tiny pores in the leaves. All life on Earth would end if there were no green vegetation. Cyanobacteria and other photosynthetic microorganisms also carry out photosynthesis.

In this article, students will learn the importance of photosynthesis along with parts of the plant involved in photosynthesis. After going through this entire article, students will be able to write the significance of photosynthesis in their exams effortlessly.

Definition of Photosynthesis

Photosynthesis (Gk. photon \({\rm{ = }}\) light; Synthesis \({\rm{ = }}\) putting together) is the most important anabolic process on our planet by which autotrophic organisms like plants synthesize complex carbohydrates from simple inorganic substances like carbon dioxide and water with the help of light energy. Carbon dioxide is fixed into carbohydrates, and light energy is converted into chemical energy.

Definition of Photosynthesis – Photosynthesis is the process of conversion of photonic energy into chemical energy by green plants.

Fig: Plant Capturing Light Energy to Perform Photosynthesis

Plants take in carbon dioxide and water in the presence of sunlight and convert them into glucose and oxygen. Oxygen is released into the atmosphere, and glucose is used for the growth and development of plants. So, plants make their food with inorganic substances in the presence of sunlight.

Fig: Equation of Photosynthesis

Parts of Plant Involved in Photosynthesis

1. Green parts of the plants like leaves, sepals and young stems are involved in photosynthesis. 2. Its cells contain organelles called Chloroplast. 3. Chloroplast (Chloros \({\rm{ = }}\) green, plastos \({\rm{ = }}\) moulded) is the green plastid that occurs in green parts of the plant. 4. Chloroplasts are mainly contained in the mesophyll cells located between the upper epidermis and lower epidermis of leaves. 5. It has a green pigment called chlorophyll (Chlor \({\rm{ = }}\) green, phyll \({\rm{ = }}\) leaf). 6. Chloroplast is a double membranous structure. 7. This envelope encloses a matrix called stroma, which contains all the necessary enzymes of photosynthesis. 8. Within the stroma, there are flattened sac-like lamellae called thylakoids, which are stacked at some places to form grana. 9. There may be \(40-50\) chloroplasts in a cell. 10. The major function of thylakoids is to perform photosynthetic light reactions. 11. Stroma is the site of dark reactions of photosynthesis. 12. Too much light destroys chlorophyll. However, the formation of chlorophyll depends upon exposure of sunlight.

Fig: Structure of Chloroplast

Products of Photosynthesis

The product of photosynthesis is glucose which is used by plants as food, and the by-product is Oxygen. These are formed from raw materials – carbon dioxide, water and sunlight. This process helps in purifying the atmosphere by consuming carbon dioxide and evolving oxygen.

Fig: Products of photosynthesis

What is Significance of Photosynthesis?

Photosynthesis is one of the most important processes in the ecosystem. It is due to the following reasons:-

• Provides Food : Each and every organism is dependent on plants, either directly or indirectly. We, humans, are also dependent on plants. Herbivores like cows, goats are directly dependent on plants, while carnivores like tigers, lions are indirectly dependent on plants. So, it can be said that herbivores are dependent on autotrophs directly while carnivores are dependent on herbivores, indirectly on plants. This chain of food dependency is called a food chain. Photosynthesis is a vital process and is responsible for the growth and sustenance of the biosphere.
• Provides Oxygen : Photosynthesis is the only process by which oxygen is evolved which is used by other organisms and plants themselves for respiration. Photosynthesis in plants is necessary to maintain the oxygen levels in the atmosphere.

Fig: Oxygen Available for Respiration

3. Ozone \(\left( {{{\rm{O}}_3}} \right)\) Formation: Molecular \({{\rm{O}}_{\rm{2}}}\) released from photosynthesis is also utilized in making ozone in the outer layer of the atmosphere. This ozone layer does not allow harmful, destructive ultraviolet radiations to get into our atmosphere. These UV rays may cause skin cancer and other related chronic diseases. 4. Formation of Carbohydrates: Carbohydrates are formed during this process which is stored in the plant body as starch and act as a food reserve, while in animals, it is stored as glycogen. 5. Formation of other Metabolites: The carbohydrates produced during photosynthesis are used by plants and animals to synthesize organic acids, proteins, fats, nucleic acids, pigments, vitamins, and other metabolites. 6. Balances \({\rm{C}}{{\rm{O}}_{\rm{2}}}\) in the Atmosphere: \({\rm{C}}{{\rm{O}}_{\rm{2}}}\) is the raw material for photosynthesis, and thus, this process helps in the removal of \({\rm{C}}{{\rm{O}}_{\rm{2}}}\) or carbon dioxide from the atmosphere, which is being added by the respiration process in us, burning of fossil fuels, etc. 7. Contribution to Carbon Cycle: Photosynthesis is responsible for the growth and sustenance of the biosphere, and the products of photosynthesis contribute to the carbon cycle occurring in the oceans, land, plants, and animals. 8. Fossil Fuels: These are the products of photosynthetic organisms, i.e. plants, algae, phytoplanktons which formed by the decomposition of these organisms when they died. 9. Other Products of Photosynthesis: In addition to organic food, plants yield fodder, firewood, timber, fibres, rubber, resins, oils, etc.

Photosynthesis is defined as a process that occurs primarily in chloroplasts and is mediated by photosynthetic pigments such as chlorophyll a, chlorophyll b, carotene, and xanthophyll. Photosynthesis uses carbon dioxide, water, and sunshine to create nutrition in green plants and a few other autotrophic species. The process of photosynthesis produces oxygen as a by-product.

Photosynthesis is the most important anabolic process on our planet by which autotrophic organisms like plants synthesize complex carbohydrates from simple inorganic substances like carbon dioxide and water with the help of light energy. Green parts of the plants like leaves, sepals and young stems are involved in photosynthesis. It has much importance like it provides food for all organisms directly or indirectly. It provides oxygen for respiration to aerobic organisms. This process also helps in balancing carbon dioxide in the atmosphere.

Also, it helps in the formation of primary and secondary metabolites which are used by different organisms for their growth and development. So, it can be concluded that photosynthesis is an essential process without which all life would come to an end.

Frequently Asked Questions (FAQs) on Significance of Photosynthesis

Q.1. What is the significance of photosynthesis? Ans: i. It provides food for all organisms either directly or indirectly. ii. It provides oxygen to aerobic organisms for respiration. iii. It balances \({\rm{C}}{{\rm{O}}_{\rm{2}}}\) in the atmosphere.

Q.2. Why is photosynthesis significant to plants? Ans : Photosynthesis significant to plants as this process helps in the formation of sugar which plants use for their growth and development. Also, it releases oxygen which is used by plants for respiration.

Q.3. What role does sunlight play in photosynthesis? Ans: Sunlight provides energy for the process of photosynthesis.

Q.4. How does photosynthesis affect humans? Ans: Photosynthesis provides oxygen to humans for their respiration. Also, carbohydrates produced by the plants are used as an energy source for humans. Excess of it is stored as glycogen for future use.

Q.5. Does photosynthesis produce oxygen? Ans: Yes, photosynthesis produces oxygen.

We hope this detailed article on ‘Significance of Photosynthesis’ helps you in your preparation. If you get stuck do let us know in the comments section below and we will get back to you at the earliest.

Related Articles

1 Million Means: 1 million in numerical is represented as 10,00,000. The Indian equivalent of a million is ten lakh rupees. It is not a...

Ways To Improve Learning Outcomes: With the development of technology, students may now rely on strategies to enhance learning outcomes. No matter how knowledgeable a...

The Three States of Matter: Anything with mass and occupied space is called ‘Matter’. Matters of different kinds surround us. There are some we can...

Motion is the change of a body's position or orientation over time. The motion of humans and animals illustrates how everything in the cosmos is...

Understanding Frequency Polygon: Students who are struggling with understanding Frequency Polygon can check out the details here. A graphical representation of data distribution helps understand...

When you receive your order of clothes or leather shoes or silver jewellery from any online shoppe, you must have noticed a small packet containing...

Visual Learning Style: We as humans possess the power to remember those which we have caught visually in our memory and that too for a...

Air Pollution: In the past, the air we inhaled was pure and clean. But as industrialisation grows and the number of harmful chemicals in the...

In biology, flowering plants are known by the name angiosperms. Male and female reproductive organs can be found in the same plant in flowering plants....

Integers Introduction: To score well in the exam, students must check out the Integers introduction and understand them thoroughly. The collection of negative numbers and whole...

Human Respiratory System – Detailed Explanation

Human Respiratory System: Students preparing for the NEET and Biology-related exams must have an idea about the human respiratory system. It is a network of tissues...

Place Value of Numbers: Detailed Explanation

Place Value of Numbers: Students must understand the concept of the place value of numbers to score high in the exam. In mathematics, place value...

The Leaf: Types, Structures, Parts

The Leaf: Students who want to understand everything about the leaf can check out the detailed explanation provided by Embibe experts. Plants have a crucial role...

Factors Affecting Respiration: Definition, Diagrams with Examples

In plants, respiration can be regarded as the reversal of the photosynthetic process. Like photosynthesis, respiration involves gas exchange with the environment. Unlike photosynthesis, respiration...

General Terms Related to Spherical Mirrors

General terms related to spherical mirrors: A mirror with the shape of a portion cut out of a spherical surface or substance is known as a...

Number System: Types, Conversion and Properties

Number System: Numbers are highly significant and play an essential role in Mathematics that will come up in further classes. In lower grades, we learned how...

Types of Respiration

Every living organism has to "breathe" to survive. The process by which the living organisms use their food to get energy is called respiration. It...

Animal Cell: Definition, Diagram, Types of Animal Cells

Animal Cell: An animal cell is a eukaryotic cell with membrane-bound cell organelles without a cell wall. We all know that the cell is the fundamental...

Conversion of Percentages: Conversion Method & Examples

Conversion of Percentages: To differentiate and explain the size of quantities, the terms fractions and percent are used interchangeably. Some may find it difficult to...

Arc of a Circle: Definition, Properties, and Examples

Arc of a circle: A circle is the set of all points in the plane that are a fixed distance called the radius from a fixed point...

Ammonia (NH3): Preparation, Structure, Properties and Uses

Ammonia, a colourless gas with a distinct odour, is a chemical building block and a significant component in producing many everyday items. It is found...

CGPA to Percentage: Calculator for Conversion, Formula, & More

CGPA to Percentage: The average grade point of a student is calculated using their cumulative grades across all subjects, omitting any supplemental coursework. Many colleges,...

Uses of Ether – Properties, Nomenclature, Uses, Disadvantages

Uses of Ether:  Ether is an organic compound containing an oxygen atom and an ether group connected to two alkyl/aryl groups. It is formed by the...

General and Middle Terms: Definitions, Formula, Independent Term, Examples

General and Middle terms: The binomial theorem helps us find the power of a binomial without going through the tedious multiplication process. Further, the use...

Mutually Exclusive Events: Definition, Formulas, Solved Examples

Mutually Exclusive Events: In the theory of probability, two events are said to be mutually exclusive events if they cannot occur simultaneously or at the...

Geometry: Definition, Shapes, Structure, Examples

Geometry is a branch of mathematics that is largely concerned with the forms and sizes of objects, their relative positions, and the qualities of space....

Bohr’s Model of Hydrogen Atom: Expressions for Radius, Energy

Rutherford’s Atom Model was undoubtedly a breakthrough in atomic studies. However, it was not wholly correct. The great Danish physicist Niels Bohr (1885–1962) made immediate...

39 Insightful Publications

Embibe Is A Global Innovator

Innovator Of The Year Education Forever

Interpretable And Explainable AI

Revolutionizing Education Forever

Best AI Platform For Education

Enabling Teachers Everywhere

Decoding Performance

Leading AI Powered Learning Solution Provider

Auto Generation Of Tests

Disrupting Education In India

Problem Sequencing Using DKT

Help Students Ace India's Toughest Exams

Best Education AI Platform

Unlocking AI Through Saas

Fixing Student’s Behaviour With Data Analytics

Leveraging Intelligence To Deliver Results

Brave New World Of Applied AI

You Can Score Higher

Harnessing AI In Education

Personalized Ed-tech With AI

Exciting AI Platform, Personalizing Education

Disruptor Award For Maximum Business Impact

Top 20 AI Influencers In India

Proud Owner Of 9 Patents

Innovation in AR/VR/MR

Best Animated Frames Award 2024

Trending Searches

Previous year question papers, sample papers.

Unleash Your True Potential With Personalised Learning on EMBIBE

Ace Your Exam With Personalised Learning on EMBIBE

Enter mobile number.

By signing up, you agree to our Privacy Policy and Terms & Conditions

• History & Society
• Science & Tech
• Biographies
• Animals & Nature
• Geography & Travel
• Arts & Culture
• Games & Quizzes
• On This Day
• One Good Fact
• New Articles
• Lifestyles & Social Issues
• Philosophy & Religion
• Politics, Law & Government
• World History
• Health & Medicine
• Browse Biographies
• Birds, Reptiles & Other Vertebrates
• Bugs, Mollusks & Other Invertebrates
• Environment
• Fossils & Geologic Time
• Entertainment & Pop Culture
• Sports & Recreation
• Visual Arts
• Demystified
• Image Galleries
• Infographics
• Top Questions
• Britannica Kids
• Saving Earth
• Space Next 50
• Student Center
• Introduction & Top Questions

Development of the idea

Overall reaction of photosynthesis.

• Basic products of photosynthesis
• Evolution of the process
• Light intensity and temperature
• Carbon dioxide
• Internal factors
• Energy efficiency of photosynthesis
• Structural features
• Light absorption and energy transfer
• The pathway of electrons
• Evidence of two light reactions
• Photosystems I and II
• Quantum requirements
• The process of photosynthesis: the conversion of light energy to ATP
• Elucidation of the carbon pathway
• Carboxylation
• Isomerization/condensation/dismutation
• Phosphorylation
• Regulation of the cycle
• Products of carbon reduction
• Photorespiration
• Carbon fixation in C 4 plants
• Carbon fixation via crassulacean acid metabolism (CAM)
• Differences in carbon fixation pathways
• The molecular biology of photosynthesis

Why is photosynthesis important?

What is the basic formula for photosynthesis, which organisms can photosynthesize.

photosynthesis

Our editors will review what you’ve submitted and determine whether to revise the article.

• Khan Academy - Photosynthesis
• Biology LibreTexts - Photosynthesis
• University of Florida - Institute of Food and Agricultural Sciences - Photosynthesis
• Milne Library - Inanimate Life - Photosynthesis
• National Center for Biotechnology Information - Chloroplasts and Photosynthesis
• Roger Williams University Pressbooks - Introduction to Molecular and Cell Biology - Photosynthesis
• BCcampus Open Publishing - Concepts of Biology – 1st Canadian Edition - Overview of Photosynthesis
• photosynthesis - Children's Encyclopedia (Ages 8-11)
• photosynthesis - Student Encyclopedia (Ages 11 and up)
• Table Of Contents

Photosynthesis is critical for the existence of the vast majority of life on Earth. It is the way in which virtually all energy in the biosphere becomes available to living things. As primary producers, photosynthetic organisms form the base of Earth’s food webs and are consumed directly or indirectly by all higher life-forms. Additionally, almost all the oxygen in the atmosphere is due to the process of photosynthesis. If photosynthesis ceased, there would soon be little food or other organic matter on Earth, most organisms would disappear, and Earth’s atmosphere would eventually become nearly devoid of gaseous oxygen.

The process of photosynthesis is commonly written as: 6CO 2 + 6H 2 O → C 6 H 12 O 6 + 6O 2 . This means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products. The sugar is used by the organism, and the oxygen is released as a by-product.

The ability to photosynthesize is found in both eukaryotic and prokaryotic organisms. The most well-known examples are plants, as all but a very few parasitic or mycoheterotrophic species contain chlorophyll and produce their own food. Algae are the other dominant group of eukaryotic photosynthetic organisms. All algae, which include massive kelps and microscopic diatoms , are important primary producers.  Cyanobacteria and certain sulfur bacteria are photosynthetic prokaryotes, in whom photosynthesis evolved. No animals are thought to be independently capable of photosynthesis, though the emerald green sea slug can temporarily incorporate algae chloroplasts in its body for food production.

Recent News

photosynthesis , the process by which green plants and certain other organisms transform light energy into chemical energy . During photosynthesis in green plants, light energy is captured and used to convert water , carbon dioxide , and minerals into oxygen and energy-rich organic compounds .

It would be impossible to overestimate the importance of photosynthesis in the maintenance of life on Earth . If photosynthesis ceased, there would soon be little food or other organic matter on Earth. Most organisms would disappear, and in time Earth’s atmosphere would become nearly devoid of gaseous oxygen. The only organisms able to exist under such conditions would be the chemosynthetic bacteria , which can utilize the chemical energy of certain inorganic compounds and thus are not dependent on the conversion of light energy.

Energy produced by photosynthesis carried out by plants millions of years ago is responsible for the fossil fuels (i.e., coal , oil , and gas ) that power industrial society . In past ages, green plants and small organisms that fed on plants increased faster than they were consumed, and their remains were deposited in Earth’s crust by sedimentation and other geological processes. There, protected from oxidation , these organic remains were slowly converted to fossil fuels. These fuels not only provide much of the energy used in factories, homes, and transportation but also serve as the raw material for plastics and other synthetic products. Unfortunately, modern civilization is using up in a few centuries the excess of photosynthetic production accumulated over millions of years. Consequently, the carbon dioxide that has been removed from the air to make carbohydrates in photosynthesis over millions of years is being returned at an incredibly rapid rate. The carbon dioxide concentration in Earth’s atmosphere is rising the fastest it ever has in Earth’s history, and this phenomenon is expected to have major implications on Earth’s climate .

Requirements for food, materials, and energy in a world where human population is rapidly growing have created a need to increase both the amount of photosynthesis and the efficiency of converting photosynthetic output into products useful to people. One response to those needs—the so-called Green Revolution , begun in the mid-20th century—achieved enormous improvements in agricultural yield through the use of chemical fertilizers , pest and plant- disease control, plant breeding , and mechanized tilling, harvesting, and crop processing. This effort limited severe famines to a few areas of the world despite rapid population growth , but it did not eliminate widespread malnutrition . Moreover, beginning in the early 1990s, the rate at which yields of major crops increased began to decline. This was especially true for rice in Asia. Rising costs associated with sustaining high rates of agricultural production, which required ever-increasing inputs of fertilizers and pesticides and constant development of new plant varieties, also became problematic for farmers in many countries.

A second agricultural revolution , based on plant genetic engineering , was forecast to lead to increases in plant productivity and thereby partially alleviate malnutrition. Since the 1970s, molecular biologists have possessed the means to alter a plant’s genetic material (deoxyribonucleic acid, or DNA ) with the aim of achieving improvements in disease and drought resistance, product yield and quality, frost hardiness, and other desirable properties. However, such traits are inherently complex, and the process of making changes to crop plants through genetic engineering has turned out to be more complicated than anticipated. In the future such genetic engineering may result in improvements in the process of photosynthesis, but by the first decades of the 21st century, it had yet to demonstrate that it could dramatically increase crop yields.

Another intriguing area in the study of photosynthesis has been the discovery that certain animals are able to convert light energy into chemical energy. The emerald green sea slug ( Elysia chlorotica ), for example, acquires genes and chloroplasts from Vaucheria litorea , an alga it consumes, giving it a limited ability to produce chlorophyll . When enough chloroplasts are assimilated , the slug may forgo the ingestion of food. The pea aphid ( Acyrthosiphon pisum ) can harness light to manufacture the energy-rich compound adenosine triphosphate (ATP); this ability has been linked to the aphid’s manufacture of carotenoid pigments.

General characteristics

The study of photosynthesis began in 1771 with observations made by the English clergyman and scientist Joseph Priestley . Priestley had burned a candle in a closed container until the air within the container could no longer support combustion . He then placed a sprig of mint plant in the container and discovered that after several days the mint had produced some substance (later recognized as oxygen) that enabled the confined air to again support combustion. In 1779 the Dutch physician Jan Ingenhousz expanded upon Priestley’s work, showing that the plant had to be exposed to light if the combustible substance (i.e., oxygen) was to be restored. He also demonstrated that this process required the presence of the green tissues of the plant.

In 1782 it was demonstrated that the combustion-supporting gas (oxygen) was formed at the expense of another gas, or “fixed air,” which had been identified the year before as carbon dioxide. Gas-exchange experiments in 1804 showed that the gain in weight of a plant grown in a carefully weighed pot resulted from the uptake of carbon, which came entirely from absorbed carbon dioxide, and water taken up by plant roots; the balance is oxygen, released back to the atmosphere. Almost half a century passed before the concept of chemical energy had developed sufficiently to permit the discovery (in 1845) that light energy from the sun is stored as chemical energy in products formed during photosynthesis.

This equation is merely a summary statement, for the process of photosynthesis actually involves numerous reactions catalyzed by enzymes (organic catalysts ). These reactions occur in two stages: the “light” stage, consisting of photochemical (i.e., light-capturing) reactions; and the “dark” stage, comprising chemical reactions controlled by enzymes . During the first stage, the energy of light is absorbed and used to drive a series of electron transfers, resulting in the synthesis of ATP and the electron-donor-reduced nicotine adenine dinucleotide phosphate (NADPH). During the dark stage, the ATP and NADPH formed in the light-capturing reactions are used to reduce carbon dioxide to organic carbon compounds. This assimilation of inorganic carbon into organic compounds is called carbon fixation.

Van Niel’s proposal was important because the popular (but incorrect) theory had been that oxygen was removed from carbon dioxide (rather than hydrogen from water, releasing oxygen) and that carbon then combined with water to form carbohydrate (rather than the hydrogen from water combining with CO 2 to form CH 2 O).

By 1940 chemists were using heavy isotopes to follow the reactions of photosynthesis. Water marked with an isotope of oxygen ( 18 O) was used in early experiments. Plants that photosynthesized in the presence of water containing H 2 18 O produced oxygen gas containing 18 O; those that photosynthesized in the presence of normal water produced normal oxygen gas. These results provided definitive support for van Niel’s theory that the oxygen gas produced during photosynthesis is derived from water.

If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

To log in and use all the features of Khan Academy, please enable JavaScript in your browser.

Middle school biology

Course: middle school biology   >   unit 3, photosynthesis in organisms.

• Understand: photosynthesis in organisms
• Apply: photosynthesis in organisms

Key points:

• Many organisms make their own food through photosynthesis . Plants, algae, and some unicellular organisms do photosynthesis.
• Photosynthesis is powered by energy from sunlight. This energy is used to rearrange atoms in carbon dioxide and water to make oxygen and sugars.
• Carbon dioxide and water are inputs of photosynthesis. These inputs come from the environment.
• The oxygen is released into the environment.
• The sugars can provide chemical energy . This energy can be used by the organism to live and grow. The sugars can also be used to build the organism’s structures, or they can be stored for later use.
• Photosynthesis is usually carried out in chloroplasts . Chloroplasts are cell structures that contain molecules called chlorophyll . Chlorophyll helps capture light energy.

Want to join the conversation?

• Upvote Button navigates to signup page
• Downvote Button navigates to signup page
• Flag Button navigates to signup page

Talk to our experts

1800-120-456-456

Photosynthesis

All you need to know about photosynthesis.

Photosynthesis is the process by which a plant produces its food by converting light energy into chemical energy. Plants use water, carbon dioxide and sunlight in the presence of chlorophyll to produce their food or energy in the form of sugar and release oxygen as the byproduct. Understanding the process of photosynthesis means a clear concept about the different cellular and chemical activities going on in the plant body. The word photosynthesis is coined from the Greek word for meaning light along with synthesis. This implies a synthesis i.e a chemical reaction using light energy. This is not always for green plants only but certain bacteria and prokaryotes also use this process to prepare their food. In green plants or algae, the synthesis takes place within an important organelle called chloroplast where the pigment chlorophyll is present. Chlorophyll occurs in their leaves, stems, flowers, sepals and even in plastids.

Factors Affecting Photosynthesis

Various factors influence/affect the photosynthesis process. These are:

Light Intensity: More the light, the more will be the rate of photosynthesis. Similarly, low light will lead to a low rate of photosynthesis.

The Concentration of CO 2 : A higher CO 2 concentration rate in a plant also accelerates the photosynthesis process. The required amount of CO 2 is 300-400 PPM.

Temperature: If the temperature is between the range of 25 to 35 degrees Celsius, photosynthesis takes place effectively.

Water: An essential amount of water is required for stomatal opening, and it’s a key factor in the process of photosynthesis.

Pollution: The increasing rate of polluting particles in the atmosphere block the pores of somatic cells, and the intake of carbon dioxide becomes difficult.

Photosynthesis Equation

Carbon dioxide and water are the two major factors involved in the photosynthesis reaction. It’s an endothermic reaction, and the products resulting from it are oxygen and glucose. The formula is:

\[6CO_{2} + 6H_{2}O = C_{6}H_{1}2O_{6} + 6O_{2}\]

However, some bacteria don’t produce oxygen as a by-product of photosynthesis. They are called anoxygenic photosynthetic bacteria, and those who do it are called oxygenic photosynthetic bacteria.

Photosynthetic Pigments

Four types of photosynthetic pigments are present in the leaves of the plants. They are:

Chlorophyll a

Chlorophyll b

Xanthophylls

Carotenoids

Structure of Chlorophyll

Chlorophyll is a green colour pigment found in plants that play a vital role in photosynthesis. It allows the plants to absorb the energy coming from the sunlight, which is essential for photosynthesis.

Process of Photosynthesis

The photosynthesis process occurs in plants. It takes place in chloroplasts at the cellular level that contains chlorophyll. Leaves have parts called the petiole, epidermis, and lamina that absorb sunlight.

Photosynthesis Steps:

The photosynthesis process takes place at two levels or steps. These are:

Light Reaction of Photosynthesis (or) Light-dependent Reaction

The process begins in the daylight, by gathering the light. The two types of photosystems convert light energy into ATP and NADPH. During their conversion, oxygen is produced, and water is used. The equation of this step is:

\[2H_{2}O + 2NADP + 3ADP + 3P_{i} = O_{2} + 2 NADPH + 3ATP\]

The Dark Reaction of Photosynthesis (or) Light-independent Reaction

This is also called carbon-fixing. It is not dependent on light and takes place in chloroplast where the products from the earlier step are used. Plants intake CO 2 and the Calvin Photosynthesis Cycle begins, where the six molecules of CO 2 are converted into sugar or glucose.

\[3CO_{2} + 6NADPH + 5H_{2}O + 9ATP = G3P + 2H + 6NADP + 9ADP + 8P_{i}\]

Importance of Photosynthesis

The photosynthesis process is very important for the survival of living beings, and to continue the food chain. It also produces oxygen, which is required for breathing.

FAQs on Photosynthesis

1. What is photosynthesis?

The process by plants, of producing nutrients essential for survival.

2. What happens in a photosynthesis process?

The nutrients and glucose required for plants, and oxygen required for the animals, is created during the process.

3. What is the photosynthesis reaction?

A reaction taking place in plants that results in the production of glucose and oxygen.

4. What is shown in a photosynthesis diagram?

The photosynthesis diagram shows how the plants take sunlight and use it to produce essential nutrients and oxygen.

5. Why is photosynthesis in plants important?

It helps in the survival of the plants, the creation of products essential for the survival of living beings, and also to maintain the environmental balance.

6. How long is the photosynthesis cycle?

The whole process of photosynthesis, right from absorbing the light up to the final stage, takes place in just 30 seconds!

7. What is included in the mechanism of photosynthesis?

The mechanism of photosynthesis is an oxidation (oxygen releasing) and reduction reaction. It produces glucose along with oxygen.

8. What are the two phases of photosynthesis?

Photosynthesis is a synthesis reaction in which solar energy gets converted to chemical energy. However, the few steps involved in the synthesis also occur without light and based on that there are two phases of photosynthesis. The light-dependent reactions and the light-independent phase. In the light-dependent phase which is the starting phase the molecule of chlorophyll pigment absorbs one photon from the sun rays and loses electrons and ultimately after several steps generate NADPH and ATP which are used in the second phase or the light-independent phase of the reaction. In the dark phase, the atmospheric carbon dioxide is captured by a photosynthetic enzyme that uses the NADPH formed in the first phase to produce 3 carbon sugars which ultimately gets converted to starch and sucrose. Thus the two phases occur subsequently to form the end products which are the food of the plant.

9. What is the efficiency of the photosynthetic reaction?

Photosynthesis is the most important reaction or synthesis for which lives and the planet can run. It converts light to chemical energy. The efficiency of the reaction is however only 3-6% and the absorbed light cannot be used. The unused light gets dissipated to the atmosphere as heat. The efficiency of the synthesis varies with temperature, light intensity and proportion of carbon dioxide in nature which can vary the efficiency to a maximum of 8% even. The efficiency of the two phases can be separately taken into count and they both separately contribute to the total efficiency of the process.

10. Which factors can affect the process of photosynthesis?

Photosynthesis is affected by many factors including the corollary ones. The main factors that affect the process are as follows:

Light: Its intensity and wavelength

Carbon dioxide: Its concentration in the atmosphere

Temperature: Favorable temperature is needed

Water: Suitable quantity of water is needed

Apart from these factors photosynthesis also depends upon the factor referred to as the corollary factor which is the surface area of the leaf available to absorb the sunlight. This is why if a plant is overshadowed by other big trees it cannot efficiently photosynthesize.

11. What are the actual stages of the process of photosynthesis?

The process of photosynthesis can be divided into four essential steps. They are as follows:

Transfer of solar energy in thylakoid membranes of chlorophyll.

Transfer of the electrons in the light reaction

The synthesis of electron transport chain and ATP in the thylakoid membrane.

Absorption and fixation of carbon dioxide from the atmosphere with the formation of resulting stable plant food.

Each of these steps takes a specific time to happen with the maximum time of one second taken by the last step.

12. How is photosynthesis essential for the ecosystem?

Photosynthesis is the procedure by which plants convert solar energy into chemical energy in the form of their food. Photosynthesis is an ideal process for a living organism that has not evolved the capacity to actively move around in order to obtain food. Photosynthesis is also important for the consumers of the food web and thus is the starting point of all food chains of the ecosystem. Photosynthesis is thus an essential living process for plants and the ecosystem.  All life on the earth depends upon photosynthesis, not only for the food but also for the oxygen in the atmosphere which is essential for them to respire. It is the process of photosynthesis that purifies the atmosphere by removing carbon dioxide from the environment and converting it to oxygen.

Biology • Class 11

ENCYCLOPEDIC ENTRY

Photosynthesis.

Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.

Loading ...

Learning materials, instructional links.

• Photosynthesis (Google doc)

Most life on Earth depends on photosynthesis .The process is carried out by plants, algae, and some types of bacteria, which capture energy from sunlight to produce oxygen (O 2 ) and chemical energy stored in glucose (a sugar). Herbivores then obtain this energy by eating plants, and carnivores obtain it by eating herbivores.

The process

During photosynthesis, plants take in carbon dioxide (CO 2 ) and water (H 2 O) from the air and soil. Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons. This transforms the water into oxygen and the carbon dioxide into glucose. The plant then releases the oxygen back into the air, and stores energy within the glucose molecules.

Chlorophyll

Inside the plant cell are small organelles called chloroplasts , which store the energy of sunlight. Within the thylakoid membranes of the chloroplast is a light-absorbing pigment called chlorophyll , which is responsible for giving the plant its green color. During photosynthesis , chlorophyll absorbs energy from blue- and red-light waves, and reflects green-light waves, making the plant appear green.

Light-dependent Reactions vs. Light-independent Reactions

While there are many steps behind the process of photosynthesis, it can be broken down into two major stages: light-dependent reactions and light-independent reactions. The light-dependent reaction takes place within the thylakoid membrane and requires a steady stream of sunlight, hence the name light- dependent reaction. The chlorophyll absorbs energy from the light waves, which is converted into chemical energy in the form of the molecules ATP and NADPH . The light-independent stage, also known as the Calvin cycle , takes place in the stroma , the space between the thylakoid membranes and the chloroplast membranes, and does not require light, hence the name light- independent reaction. During this stage, energy from the ATP and NADPH molecules is used to assemble carbohydrate molecules, like glucose, from carbon dioxide.

C3 and C4 Photosynthesis

Not all forms of photosynthesis are created equal, however. There are different types of photosynthesis, including C3 photosynthesis and C4 photosynthesis. C3 photosynthesis is used by the majority of plants. It involves producing a three-carbon compound called 3-phosphoglyceric acid during the Calvin Cycle, which goes on to become glucose. C4 photosynthesis, on the other hand, produces a four-carbon intermediate compound, which splits into carbon dioxide and a three-carbon compound during the Calvin Cycle. A benefit of C4 photosynthesis is that by producing higher levels of carbon, it allows plants to thrive in environments without much light or water. The National Geographic Society is making this content available under a Creative Commons CC-BY-NC-SA license . The License excludes the National Geographic Logo (meaning the words National Geographic + the Yellow Border Logo) and any images that are included as part of each content piece. For clarity the Logo and images may not be removed, altered, or changed in any way.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Production Managers

Program specialists, last updated.

June 21, 2024

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our Terms of Service .

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources

CBSE Class Notes Online – Classnotes123

CBSE Class Notes, Worksheets, Question Answers, Diagrams , Definitions , Diffrence between , Maths Concepts, Science Facts Online – Classnotes123

Photosynthesis – Class 10

Photosynthesis is a fundamental process that occurs in green plants and certain bacteria. It is an autotrophic mode of nutrition wherein organisms synthesise their food from simple inorganic substances such as carbon dioxide and water in the presence of sunlight.

Table of Contents

Definition of Photosynthesis

Photosynthesis is a complex biochemical process that occurs in the green parts of plants, such as leaves, stems, and sometimes in other green tissues. It is the primary mechanism by which plants produce their own food, using energy from sunlight to convert inorganic substances into organic compounds.

Modes of Autotrophic Nutrition

Autotrophic mode of nutrition refers to the mode of nutrition in which organisms synthesise their own food from simple inorganic substances present in the environment. Two common modes of autotrophic nutrition are- – 

• Photosynthesis – Photosynthesis is the primary mode of autotrophic nutrition used by green plants and some bacteria. It is the process by which green plants synthesise organic food using carbon dioxide, water, sunlight, and chlorophyll.
• Chemosynthesis – Chemosynthesis is another mode of autotrophic nutrition used by certain bacteria that live in extreme environments, such as deep-sea hydrothermal vents. These bacteria utilise energy obtained from chemical reactions involving inorganic compounds to produce organic food.

Significance of Photosynthesis

• Production of Organic Food – Through Photosynthesis, green plants convert carbon dioxide and water into glucose, a simple sugar that serves as their primary source of energy. This energy is utilised for various metabolic processes required for growth, reproduction, and maintenance of cellular functions.
• Energy Storage- Carbohydrates, primarily in the form of glucose, are produced during Photosynthesis. These carbohydrates provide energy to the plant for immediate use. Any excess carbohydrates that are not immediately utilised are converted into starch and stored as an internal energy reserve. This stored energy is available to the plant whenever required.
• Oxygen Release- As a byproduct of Photosynthesis, oxygen is released into the atmosphere. This oxygen is essential for the survival of all living organisms, as it is used in cellular respiration to produce energy.

Also Check – Diffrence Between Photosynthesis and Respiration

Process of Photosynthesis

Photosynthesis occurs in the specialised organelles called chloroplasts, which are present in the cells of green plant tissues, particularly in leaves. The process can be divided into two main stages- 

• The light-dependent reactions 
• The light-independent reactions (Calvin cycle)

Light-Dependent Reactions

In the thylakoid membranes of chloroplasts, light energy is absorbed by chlorophyll, initiating the following steps-

• Absorption of Light Energy- Chlorophyll, the green pigment present in chloroplasts, absorbs light energy from the sun.
• Splitting of Water Molecules- The absorbed light energy is used to split water molecules (H2O) into oxygen (O2) and hydrogen ions (H+).
• Generation of ATP and NADPH- The energy from the absorbed light is harnessed to produce ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which serve as energy carriers for the subsequent reactions.

Light-Independent Reactions (Calvin Cycle)

In the stroma of chloroplasts, the light-independent reactions occur and involve the following steps-

• Carbon Dioxide Fixation- Carbon dioxide (CO2) from the atmosphere combines with the hydrogen ions (H+) and energy carriers (ATP and NADPH) to form an intermediate molecule.
• Production of Glucose- The intermediate molecule undergoes a series of enzymatic reactions, ultimately leading to the production of glucose (C6H12O6).
• Regeneration of Reactants- Some molecules from the intermediate stage are recycled to regenerate the starting materials, ATP, NADPH, and carbon dioxide acceptors, allowing the process to continue.

Overall Equation for Photosynthesis

The process of Photosynthesis can be represented by the following simplified chemical equation-

6CO2 + 6H2O + Light Energy → C6H12O6 + 6O2

In this equation, carbon dioxide (CO2) and water (H2O) are the raw materials, and in the presence of light energy, glucose (C6H12O6) and oxygen (O2) are produced.

The Raw Materials for Photosynthesis

Photosynthesis requires specific raw materials for the process to occur efficiently. The essential raw materials for Photosynthesis are carbon dioxide (CO2), water (H2O), and other mineral nutrients obtained from the soil. Let’s delve into each of these raw materials and their role in Photosynthesis-

Carbon Dioxide (CO2)

• Carbon dioxide is a colourless and odourless gas that is released into the atmosphere as a byproduct of cellular respiration in living organisms. 
• During cellular respiration, organisms, including plants, break down organic molecules to release energy. In turn, they release carbon dioxide as a waste product.
• For plants, carbon dioxide enters the leaves through tiny openings called stomata. Stomata are present on the surface of leaves and allow for the exchange of gases between the plant and the environment. 
• Carbon dioxide diffuses into the leaf through the stomata, providing the necessary carbon source for Photosynthesis.

Also Check – Mechanism of opening and Closing of the Stomata

Water (H2O)-

• Water is another crucial raw material required for Photosynthesis. Plants absorb water through their roots from the soil. 
• The root hairs, which are extensions of root cells, increase the surface area for water absorption.
• Once absorbed, water is transported upward through the plant’s vascular system, specifically through a specialised tissue called xylem. 
• The xylem vessels extend from the roots all the way to the leaves. The movement of water through xylem is driven by a combination of root pressure and transpiration , the loss of water vapour through small openings on the leaf surface called stomata.
• During Photosynthesis, water molecules are split in a process called photolysis. This splitting occurs in the presence of sunlight and takes place in the chloroplasts of the plant cells. 
• The photolysis of water results in the production of oxygen gas (O2) and hydrogen ions (H+). The oxygen is released into the atmosphere as a byproduct of Photosynthesis, while the hydrogen ions are used in subsequent reactions.

Other Materials- Mineral Nutrients

• In addition to carbon dioxide and water, plants require various mineral nutrients obtained from the soil for optimal growth and Photosynthesis. 
• These mineral nutrients include nitrogen (N), phosphorus (P), iron (Fe), and magnesium (Mg), among others.
• Nitrogen is an essential nutrient that plants require for the synthesis of proteins and other vital compounds. Plants uptake nitrogen from the soil in the form of inorganic nitrates (or nitrites) or as organic compounds derived from symbiotic relationships with nitrogen-fixing bacteria.
• Phosphorus is necessary for energy transfer and storage in plants. It is obtained from the soil in the form of inorganic phosphates and plays a critical role in various metabolic processes.
• Iron is a micronutrient essential for chlorophyll synthesis. It is involved in capturing light energy during Photosynthesis. Plants absorb iron in the form of inorganic ions from the soil.
• Magnesium is a central component of chlorophyll, the pigment responsible for capturing light energy during Photosynthesis. Plants absorb magnesium as an inorganic ion from the soil.
• These mineral nutrients are absorbed by the plant’s roots and transported through the vascular system to the cells where Photosynthesis occurs. They are crucial for the plant’s overall growth, development, and efficient photosynthetic processes. Read More ..

The Site of Photosynthesis- Chloroplasts

Photosynthesis takes place within specialised organelles called chloroplasts, which are present in the cells of green plants. Chloroplasts play a crucial role as the primary sites of Photosynthesis. Let’s explore the structure of chloroplasts, their presence in photosynthetic cells, and the role of chlorophyll in capturing light energy.

Structure of Chloroplasts

Chloroplasts are unique double-membrane organelles found in the cells of plants, algae, and some other organisms capable of Photosynthesis. These organelles contain an intricate network of membranes, enzymes, and pigments that facilitate the process of Photosynthesis.

Within the chloroplasts, there are several key structures-

• Outer Membrane- The outer membrane of the chloroplast acts as a protective barrier, separating the internal contents from the surrounding cytoplasm of the cell.
• Inner Membrane- The inner membrane is located inside the outer membrane and encloses the stroma, a gel-like substance where the light-independent reactions of Photosynthesis occur.
• Thylakoid Membranes- The thylakoid membranes are interconnected sac-like structures that are stacked on top of each other in a structure called a grana (plural- granum). These membranes contain specialised pigments, including chlorophyll, that capture light energy.
• Stroma- The stroma is the fluid-filled space within the chloroplast that surrounds the thylakoid membranes. It contains enzymes and other molecules necessary for the light-independent reactions of Photosynthesis.

Also Check – Chloroplast – Definition, Structure, Distribution, function and Diagram

Presence of Chloroplasts in Photosynthetic Cells

Chloroplasts are primarily found in the photosynthetic cells of green plants, particularly in the mesophyll cells of leaves. The mesophyll cells are specialised for Photosynthesis and contain numerous chloroplasts. This arrangement maximises the surface area available for light capture and ensures efficient photosynthetic processes.

Chlorophyll and Light Absorption

• Chlorophyll is a green pigment found within the chloroplasts that plays a vital role in capturing light energy during Photosynthesis. It is responsible for the characteristic green colour of plants.
• Chlorophyll molecules are embedded in the thylakoid membranes of chloroplasts. These molecules have a unique structure that allows them to absorb light energy from the visible spectrum, particularly in the red and blue regions, while reflecting green light.
• When light strikes chlorophyll molecules, they absorb photons of specific wavelengths. The absorbed light energy is then transferred to other chlorophyll molecules and ultimately to the reaction centres in the thylakoid membranes. This energy is used to drive the chemical reactions of Photosynthesis, converting light energy into chemical energy stored in the form of ATP and NADPH.

Conditions Necessary for Photosynthesis

For Photosynthesis to occur, certain conditions must be met. These conditions include the availability of sunlight and the presence of chlorophyll. Let’s explore the significance of these conditions in detail-

Sunlight is a crucial factor in Photosynthesis as it provides the energy needed for the process. The intensity, quality, and duration of sunlight all influence the rate of Photosynthesis.

• Intensity- The intensity of sunlight refers to the amount of light energy reaching a given area. Higher light intensity generally leads to increased photosynthetic activity. However, there is an optimal range of light intensity beyond which the rate of Photosynthesis plateaus. Insufficient light intensity limits the amount of energy available for the process.
• Quality – Sunlight consists of a spectrum of colours, each with a different wavelength. Plants primarily absorb light in the red and blue regions of the spectrum, while green light is reflected, giving plants their green appearance. Thus, the quality of light, specifically the presence of red and blue wavelengths, is essential for efficient Photosynthesis.
• Duration- The duration of exposure to sunlight also affects Photosynthesis. Longer periods of light availability allow for a greater accumulation of energy, leading to increased photosynthetic activity. However, plants also have mechanisms to adapt to changing light conditions, such as adjusting the opening and closing of stomata to optimise gas exchange and reduce water loss.

Chlorophyll

Chlorophyll is a pigment found in chloroplasts, and it plays a pivotal role in capturing solar energy during Photosynthesis.

• Trapping Solar Energy- Chlorophyll molecules are responsible for absorbing light energy from the sun. Specifically, chlorophyll molecules absorb photons of light in the red and blue regions of the spectrum. This absorbed energy is then transferred to other molecules within the chloroplast, leading to the initiation of the light-dependent reactions of Photosynthesis.
• Chlorophyll molecules are arranged within the thylakoid membranes of the chloroplasts, maximising their exposure to light. This organisation allows for efficient light absorption and energy transfer.
• It is important to note that other pigments, such as carotenoids, also contribute to light absorption in plants. These pigments capture light energy in different regions of the spectrum and help supplement the overall efficiency of Photosynthesis.

Events in Photosynthesis

Photosynthesis involves a series of interconnected events that occur within the chloroplasts of plant cells. These events are essential for converting light energy into chemical energy and synthesise carbohydrates. Let’s explore these events in detail-

Absorption of Light Energy-

During Photosynthesis, chlorophyll, the primary pigment in chloroplasts, plays a crucial role in absorbing light energy from the sun. Chlorophyll molecules are located in the thylakoid membranes of chloroplasts and are arranged to maximise light absorption.

When chlorophyll molecules absorb photons of specific wavelengths, they become energised. This absorbed energy is transferred to neighbouring chlorophyll molecules until it reaches specialised structures called reaction centres. These reaction centers initiate the conversion of light energy into chemical energy.

Conversion of Light Energy

The absorbed light energy is utilized in the light-dependent reactions of Photosynthesis to produce energy-rich molecules such as ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). These energy carriers serve as the “currency” for the subsequent synthesis of carbohydrates.

Additionally, during the light-dependent reactions, water molecules are split through a process called photolysis. The energy absorbed by chlorophyll facilitates the separation of water molecules into hydrogen ions (H+) and oxygen (O2). This release of oxygen is vital for the oxygenation of our atmosphere, while the hydrogen ions are further utilised in the synthesis of carbohydrates.

Reduction of Carbon Dioxide

In the light-independent reactions, also known as the Calvin cycle, the energy-rich molecules (ATP and NADPH) generated in the light-dependent reactions are used to convert carbon dioxide (CO2) into carbohydrates.

During this process, carbon dioxide molecules from the atmosphere enter the chloroplasts and undergo a series of chemical reactions. The energy from ATP and the high-energy electrons from NADPH are utilised to drive the reduction of carbon dioxide. The end result is the synthesis of simple sugars, such as glucose, which serve as a vital source of energy and building blocks for the plant.

It’s important to note that the events in Photosynthesis do not occur sequentially in a strict order. Instead, they are interconnected and continually ongoing, with various stages and reactions happening simultaneously or in response to changing environmental conditions.

Also Check – Top 10 Experiments on Photosynthesis (With Diagram)

Factors Affecting Photosynthesis

• Temperature- Photosynthesis is temperature-sensitive, with the optimal range for most plants typically being between 20-30 degrees Celsius (68-86 degrees Fahrenheit). Higher temperatures can initially increase the rate of photosynthesis, but excessive heat can damage the enzymes involved in the process.
• Carbon dioxide (CO2) concentration- Carbon dioxide is an important raw material for photosynthesis. Higher CO2 concentrations can increase the rate of photosynthesis, up to a certain point where it becomes saturated. Insufficient CO2 can limit the photosynthetic process.
• Light intensity- Light is an essential factor for photosynthesis as it provides the energy needed to convert carbon dioxide and water into glucose and oxygen. Higher light intensity usually increases the rate of photosynthesis, but beyond a certain threshold the rate stagnates.
• Light quality- Plants absorb mainly red and blue wavelengths of light, while green light is reflected, which is why plants appear green. Different wavelengths and light spectra can affect the photosynthesis rate differently. Certain plants have specific light requirements.
• Availability of water- Water is crucial for photosynthesis as it provides the hydrogen ions necessary for the synthesis of glucose. Insufficient water supply can lead to closure of the stomata, reducing CO2 uptake and limiting the rate of photosynthesis.
• Availability of nutrients- Plants require various nutrients, including nitrogen, phosphorus, potassium and trace elements, to carry out photosynthesis effectively. An insufficient supply of nutrients can limit the production of enzymes and other components involved in this process.
• Chlorophyll content- Chlorophyll is the most important pigment responsible for the absorption of light energy during photosynthesis. Plants with a higher chlorophyll content tend to have a greater capacity for photosynthesis.
• Environmental factors- Factors such as altitude, humidity and air pollutants can affect photosynthesis. Extreme conditions such as high altitude or pollution can affect the availability of light, temperature and CO2, thus affecting the rate of photosynthesis. Read More..

Adaptations and Additional Photosynthesis Information 

Photosynthesis is a remarkable process that has evolved various adaptations to suit different environmental conditions. These adaptations allow plants to optimise their photosynthetic efficiency and ensure survival in diverse habitats. Let’s explore some of these unique adaptations and additional information related to Photosynthesis-

Desert Plants Adaptation

Desert plants, such as cacti and certain succulents, have adapted to conserve water in arid environments. To minimise water loss through transpiration, they have developed a unique adaptation known as Crassulacean Acid Metabolism (CAM). CAM plants open their stomata and take in carbon dioxide during the cooler nights when evaporation rates are lower. The carbon dioxide is then stored as an intermediate compound, typically malic acid, within the cells. During the day, when the stomata are closed to prevent water loss, the stored carbon dioxide is released and used for Photosynthesis. This adaptation allows desert plants to conserve water while still performing Photosynthesis efficiently.

Also Check- What are the Adaptations of leaf for Photosynthesis

Aquatic Plants’ Adaptation

• Aquatic plants, such as Hydrilla and Vallisneria, have adapted to living in waterlogged environments. Unlike terrestrial plants that primarily obtain carbon dioxide from the atmosphere, these plants can use dissolved carbon dioxide present in the water for Photosynthesis. They possess specialised structures that facilitate the uptake of dissolved carbon dioxide directly from their aquatic surroundings. This adaptation enables them to thrive in aquatic habitats where access to atmospheric carbon dioxide is limited.

Additional Information

Photosynthesis and oxygen production.

Photosynthesis is responsible for oxygen production, which is vital for supporting life on Earth. The oxygen released as a byproduct during the splitting of water molecules in the light-dependent reactions of Photosynthesis contributes to the oxygenation of our atmosphere, making it suitable for aerobic organisms.

Nitrogen is taken up in the form of inorganic nitrates (or nitrites) or as organic compounds prepared by symbiotic bacteria like Rhizobium from Atmospheric nitrogen .

Photosynthetic Pigments and Leaf Coloration

Besides chlorophyll, other pigments, such as carotenoids, play a role in Photosynthesis. These pigments absorb light in different regions of the spectrum, enhancing the range of light wavelengths that can be utilised for Photosynthesis. Carotenoids also provide colours like yellow, orange, and red to leaves, contributing to the vibrant autumn foliage.

Also Check- Steps of Photosynthesis

Photosynthesis – frequently asked questions and answers.

What is Photosynthesis?

Answer- Photosynthesis is a complex biochemical process that occurs in the green parts of plants, using energy from sunlight to convert inorganic substances (carbon dioxide and water) into organic compounds (glucose) as a means of producing food.

What are the two common modes of autotrophic nutrition?

Answer- The two common modes of autotrophic nutrition are Photosynthesis and chemosynthesis.

How do green plants obtain their energy through Photosynthesis?

Answer- Green plants obtain their energy through Photosynthesis by converting carbon dioxide and water into glucose, a simple sugar that serves as their primary source of energy.

What is the significance of Photosynthesis in terms of energy storage?

Answer- Photosynthesis allows plants to produce carbohydrates, primarily in the form of glucose, which provide immediate energy for the plant. Any excess carbohydrates not immediately used are converted into starch and stored as an internal energy reserve.

How does Photosynthesis contribute to the oxygen levels in the atmosphere?

Answer- As a byproduct of Photosynthesis, oxygen is released into the atmosphere. This oxygen is essential for the survival of all living organisms, as it is used in cellular respiration to produce energy.

Which organelle is responsible for Photosynthesis in green plant tissues?

Answer- Photosynthesis occurs in specialised organelles called chloroplasts, which are present in the cells of green plant tissues, particularly in leaves.

What are the two main stages of Photosynthesis?

Answer- The two main stages of Photosynthesis are the light-dependent reactions and the light-independent reactions (Calvin cycle).

What happens during the light-dependent reactions of Photosynthesis?

Answer- In the light-dependent reactions, light energy is absorbed by chlorophyll, leading to the splitting of water molecules into oxygen and hydrogen ions. The energy from the absorbed light is used to produce ATP and NADPH, which serve as energy carriers for the subsequent reactions.

What occurs during the light-independent reactions (Calvin cycle) of Photosynthesis?

Answer- During the light-independent reactions, carbon dioxide from the atmosphere combines with hydrogen ions and energy carriers (ATP and NADPH) to form an intermediate molecule, which undergoes enzymatic reactions ultimately leading to the production of glucose. Some molecules from the intermediate stage are recycled to regenerate the starting materials, allowing the process to continue.

Provide the overall chemical equation for Photosynthesis.

Answer- The overall equation for Photosynthesis is: 6CO2 + 6H2O + Light Energy → C6H12O6 + 6O2. In this equation, carbon dioxide and water are the raw materials, and in the presence of light energy, glucose and oxygen are produced.

What are the three essential raw materials required for Photosynthesis?

Answer- The three essential raw materials required for Photosynthesis are carbon dioxide (CO2), water (H2O), and mineral nutrients obtained from the soil.

What is the process called when water molecules are split during Photosynthesis?

Answer- The process of water molecule splitting during Photosynthesis is called photolysis.

Name two mineral nutrients required by plants for optimal growth and Photosynthesis.

Answer- Two mineral nutrients required by plants for optimal growth and Photosynthesis are nitrogen (N) and phosphorus (P).

Where does Photosynthesis take place within the cells of green plants?

Answer- Photosynthesis takes place within specialised organelles called chloroplasts, which are present in the cells of green plants.

What are the key structures within chloroplasts?

Answer- The key structures within chloroplasts include the outer membrane, inner membrane, thylakoid membranes, and stroma.

Which pigment is responsible for capturing light energy during Photosynthesis?

Answer- Chlorophyll is the pigment responsible for capturing light energy during Photosynthesis.

What wavelengths of light are absorbed by chlorophyll?

Answer- Chlorophyll absorbs light energy from the red and blue regions of the visible spectrum while reflecting green light.

How is the absorbed light energy used during Photosynthesis?

Answer- The absorbed light energy is used to drive the chemical reactions of Photosynthesis, converting light energy into chemical energy stored in the form of ATP and NADPH.

In which cells of plants are chloroplasts primarily found?

Answer- Chloroplasts are primarily found in the photosynthetic cells of green plants, particularly in the mesophyll cells of leaves.

What are the essential raw materials required for Photosynthesis?

Answer- The essential raw materials for Photosynthesis are carbon dioxide (CO2), water (H2O), and other mineral nutrients obtained from the soil.

How does carbon dioxide enter the leaves of plants?

Answer- Carbon dioxide enters the leaves of plants through tiny openings called stomata, which are present on the surface of leaves.

Where does water absorption occur in plants?

Answer- Water is absorbed by plants through their roots from the soil.

Which specialised tissue transports water from the roots to the leaves?

Answer- The xylem, a specialised tissue, transports water from the roots to the leaves.

What is the role of chlorophyll in Photosynthesis?

Answer- Chlorophyll is a pigment that captures light energy during Photosynthesis. It absorbs photons of specific wavelengths, particularly in the red and blue regions of the spectrum.

What are the primary factors influencing the rate of Photosynthesis?

Answer- The primary factors influencing the rate of Photosynthesis are light intensity, light quality, temperature, carbon dioxide concentration, and the availability of water and nutrients.

How does light energy get converted into chemical energy during Photosynthesis?

Answer- Light energy is converted into chemical energy during Photosynthesis through the light-dependent reactions, where chlorophyll molecules absorb light and transfer the energy to generate energy-rich molecules such as ATP and NADPH.

What is the role of ATP and NADPH in Photosynthesis?

Answer- ATP and NADPH are energy carriers produced during the light-dependent reactions of Photosynthesis. They provide the energy and reducing power needed for the light-independent reactions to convert carbon dioxide into carbohydrates.

What are some adaptations of desert plants for Photosynthesis in arid environments?

Answer- Desert plants, such as cacti, have adapted a process called Crassulacean Acid Metabolism (CAM). They open their stomata at night to take in carbon dioxide and store it as malic acid. During the day, the stored carbon dioxide is released for Photosynthesis when the stomata are closed to minimise water loss.

How do aquatic plants obtain carbon dioxide for Photosynthesis? Answer- Aquatic plants can use dissolved carbon dioxide present in the water for Photosynthesis. They have specialised structures that facilitate the uptake of dissolved carbon dioxide from their aquatic surroundings.

Related Posts

What is a reflex action – for class 10th.

February 10, 2024 March 16, 2024

What is Reflex Arc for Class 10

February 9, 2024 February 10, 2024

What is Interstitial Fluid and its Vital Role in Cellular Health and Function

February 9, 2024 February 9, 2024

About Jaishree Gorane

19 comments on “photosynthesis – class 10”.

• Pingback: SIGNIFICANCE OF TRANSPIRATION - CBSE Class Notes Online - Classnotes123
• Pingback: How are Water and Minerals Transported in Plants ? - CBSE Class Notes Online - Classnotes123
• Pingback: How do the Guard cells Regulate Opening and Closing of Stomatal Pores - CBSE Class Notes Online - Classnotes123
• Pingback: Name the Factors Which Affect Photosynthesis - CBSE Class Notes Online - Classnotes123
• Pingback: Cross Section of Leaf Class 10 - CBSE Class Notes Online - Classnotes123
• Pingback: What are the Adaptations of leaf for Photosynthesis - CBSE Class Notes Online - Classnotes123
• Pingback: Difference between Potosynthesis and Respiration - CBSE Class Notes Online - Classnotes123
• Pingback: What is Photosynthesis? Explain the mechanism. - CBSE Class Notes Online - Classnotes123
• Pingback: Autotrophic Nutrition - Class 10 - CBSE Class Notes Online - Classnotes123
• Pingback: Life Processes Class 10 Notes - CBSE Class Notes Online - Classnotes123
• Pingback: What is the Function of the Stomata ? - CBSE Class Notes Online - Classnotes123
• Pingback: What is Photosynthesis Short Answer - CBSE Class Notes Online - Classnotes123
• Pingback: Nutrition in Plants Class 10 - CBSE Class Notes Online - Classnotes123
• Pingback: Diagram of a Chloroplast - CBSE Class Notes Online - Classnotes123
• Pingback: Transverse Section of Leaf - CBSE Class Notes Online - Classnotes123
• Pingback: What are the Components of Transport System in Highly Organised Plants - CBSE Class Notes Online - Classnotes123
• Pingback: Transportation in Plants Class 10 - CBSE Class Notes Online - Classnotes123
• Pingback: How is Food Transported in Plants -Class 10 - CBSE Class Notes Online - Classnotes123
• Pingback: Chloroplast - Definition, Structure, Distribution, function and Diagram - CBSE Class Notes Online - Classnotes123

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Explain the mechanism of photosynthesis.

Photosynthesis is the process by which green plants prepare their food in the presence of sunlight. green plants utilize carbon dioxide and water to make carbohydrate. the reaction of photosynthesis can be depicted in the following equation: $$6co_2+12h_2o\xrightarrow{chlorophyll+sunlight}c_6h_12o_6+6o_2+6h_2o$$ the process of photosynthesis is composed of following step: (a) absorption of light energy by chlorophyll. (b) conversion of light energy into chemical energy (c) splitting of water molecules into hydrogen and oxygen. (d) reduction of carbon dioxide to form carbohydrate these steps need not take place one after another immediately. for example; desert plants take up carbon dioxide at night to make an intermediate. during daytime. they make carbohydrate. after photosynthesis, carbohydrate is converted into starch and starch is stored in different plant organs..

explain the mechanism of photosynthesis?

Question 79 Explain the mechanism of photosynthesis.

• Biology Article
• Photorespiration

Table of Contents

• Photosynthesis
• Important Questions

When the carbon dioxide concentration inside a leaf drops, photorespiration takes place. This takes place mostly on warm arid days when plants are compelled to shut their stomata to avert surplus water loss. The oxygen proportions of the leaf will automatically surge if the plants keep trying to fix carbon dioxide when their stomata are shut, all the carbon dioxide stored will be consumed and the oxygen proportions will surge when compared to carbon dioxide levels.

What is Photorespiration

Photorespiration is a process that occurs in Calvin Cycle during plant metabolism. In this process, the key enzyme RuBisCO that is responsible for The fixing of carbon dioxide reacts with oxygen rather than carbon dioxide. It occurs because of the conditions in which carbon dioxide concentration falls down and rubisco does not have enough carbon dioxide to fix and it starts fixing oxygen. Under suitable conditions, C3 plants have sufficient water, the supply of carbon dioxide is abundant and in such conditions, photorespiration is not a problem.

Photorespiration is influenced by high temperature as well as light intensity and accelerating the formation of glycolate and the flow through the photorespiratory pathway.

Photorespiration causes a light-reliant acceptance of O2 and discharge of CO2 and is related to the creation and metabolism of a minute particle named glycolate.

Photosynthesis and photorespiration are two biological processes (in flourishing plants) that can function simultaneously beside each other as photosynthesis gives off oxygen as its byproduct and photorespiration gives off carbon dioxide as its byproduct, and the said gases are the raw material for the said processes.

When the carbon dioxide levels inside the leaf dip to about 50 ppm, RuBisCO begins combining Oxygen with RuBP as an alternative to Carbon dioxide.

The final result of this is that as an alternative to manufacturing 2 molecules of 3C- PGA units, merely one unit of PGA is fashioned with a noxious 2C molecule termed phosphoglycolate.

To purge themselves of the phosphoglycolate the plant takes some steps . Primarily, it instantly purges itself from the phosphate cluster, transforming those units into glycolic acid. After that, this glycolic acid is transferred to the peroxisome and then transformed into glycine. The conversion of glycine into serine takes place in the mitochondria of the plant cell . The serine produced after that is used to create other organic units. This causes a loss of carbon dioxide from the flora as these reactions charge plant’s energy.

Also Read:   Photosynthesis

To avert this procedure, two dedicated biochemical reactions were necessary to evolve in the flora of our world:

Photosynthesis in C4 plants

Plants that propagate in warm, arid climates similar to sugarcane and corn have developed a dissimilar system for carbon dioxide fixation. The structure of the leaves of these plants is dissimilar to that of a normal leaf. They are known to display Kranz anatomy. Dense-walled parenchyma cells termed as bundle sheath cells surround the phloem and xylem of these leaves where the maximum amount of photosynthesis happens.

Also Refer:   The Plant Tissue System

CAM – Crassulacean Acid Metabolism

  This section of flora makes use of a procedure akin to the C4 section apart from the fact that they take carbon dioxide in nocturnal hours and convert it into malic or aspartic acid. The vacuoles of their photosynthetic cells provide a location to store them. As soon as the sun shines these plants shut their stomata and disintegrate the malic acid to keep the carbon dioxide ratio high enough to avert photorespiration. This permits the leaves to have their stomata shut with the intention of preventing withering. This section of flora doesn’t display Kranz anatomy.

Also Read:  Stomata

For more information about the Photorespiration, its process and other related topics, visit us at  BYJU’S Biology.

Important Questions on Photorespiration

Q.1.What is  Photorespiration? Sol.  P hotorespiration  can be defined as the evolution of carbon dioxide(CO 2 ) during photosynthesis.

Q.2.What is  Photosynthesis? Sol.  Photosynthesis is a biological process, which uses light energy (sunlight) to synthesise organic compounds.

Q.3.Which light range is most effective in photosynthesis? Sol. Red light.

Q.4.What is the function of RuBisCO in photorespiration?

Sol.  In photorespiration, RuBisCO catalyses the oxygenation of RuBP to one molecule of PGA and phosphoglycolate.

Q.5.What is the difference between photosynthesis and photorespiration?

Sol. Photosynthesis and photorespiration are different processes. In photosynthesis, carbon dioxide fixation takes place by the RuBisCO, whereas in the photorespiration RuBisCO reacts with oxygen and it competes with the Calvin cycle.

Put your understanding of this concept to test by answering a few MCQs. Click ‘Start Quiz’ to begin!

Select the correct answer and click on the “Finish” button Check your score and answers at the end of the quiz

Visit BYJU’S for all Biology related queries and study materials

Your result is as below

Request OTP on Voice Call

Leave a Comment Cancel reply

Your Mobile number and Email id will not be published. Required fields are marked *

Post My Comment

Register with BYJU'S & Download Free PDFs

Register with byju's & watch live videos.