Plants are the autotrophic organisms that synthesize their own food with the help of naturally available raw material like water, carbon dioxide and light. This process is called photosynthesis. There is more to it behind this term which involves complex processes and chemical reactions. Let's move forward and understand the word equation for the photosynthesis process with proper chemical reactions.

What is Photosynthesis?

‘Photo’ means ‘light’ and ‘synthesis’ means ‘making’. Thus, photosynthesis is a photobiochemical reaction that occurs majorly in plants (also in green algae and some bacteria) to make food utilising the sunlight, carbon dioxide, and water. The end products of this reaction are glucose and oxygen.

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What is the Process of Photosynthesis?

Photosynthesis is the natural process by which green plants, algae, and some bacteria produce their own food using sunlight. It takes place mainly in the leaves of the plant, where a green pigment called chlorophyll captures the energy from sunlight. During this process, plants absorb carbon dioxide (CO₂) from the air through small openings called stomata and water (H₂O) from the soil through their roots. With the help of sunlight, these two ingredients undergo a chemical reaction inside the plant to form glucose (a type of sugar used for energy and growth) and oxygen (O₂), which is released into the air.

Steps of Photosynthesis in Order

If we break the photosynthesis into steps then it will be a multiple step process. If we talk about the stages then there are two stages of photosynthesis, light reaction and dark reaction. Lets first discuss the photosynthesis steps in order:

Raw Material of Photosynthesis

There are major three photosynthesis raw materials, water, carbon dioxide, and sunlight. Chlorophyll is not a raw material but a necessary pigment for photosynthesis that absorbs the sunlight and excites the electrons through electron transport chain to run the photosynthesis reaction. It is present inside the chloroplast. Check here all three raw materials of photosynthesis reaction with their roles.

Products of Photosynthesis

The end product of photosynthesis is glucose and oxygen. Glucose utilised by plants to run various biochemical processes and oxygen is released into atmosphere. Check the photosynthesis products and their roles from below:

Photosynthesis Equation

Photosynthesis can be explained through chemical as well as word equations. The word equation is majorly used to describe the process in junior standards. At a higher level, questions have been asked on the chemical equation of photosynthesis. Let's understand them one by one.

Word Equation of Photosynthesis

The simple equation for photosynthesis in words can be seen below. This is the best way to represent a photosynthesis reaction to reflect complete and clear understanding.

Chemical Equation of Photosynthesis

The photosynthesis chemical equation is not very different from its photosynthesis word equation. Here, we only mention the elements instead of their names. The numbers along with each element or compound are used to depict their number of atoms involved. Thus, it helps in balancing the chemical equation. The chemical equation of photosynthesis is given below:

What is the Basic Formula of Photosynthesis?

Photosynthesis is a light-energized oxidation-reduction process where the energy of light is used to oxidize water (H₂O), producing oxygen gas (O₂), hydrogen ions (H⁺), and electrons. Most of these electrons and hydrogen ions are transferred to carbon dioxide (CO₂), which is reduced to organic products. The basic formula of photosynthesis describes the chemical reaction that occurs when plants convert carbon dioxide from the atmosphere and water molecules into chemical energy in the presence of light. This basic formula for the process of photosynthesis is represented as a balanced chemical equation –

Sunlight + CO₂ + H₂O → Glucose (C₆H₁₂O₆) + Oxygen (O₂).

This equation is expressed in words as follows –

“Six molecules of carbon dioxide (6CO₂) plus six molecules of water (6H₂O), in the presence of light energy and chlorophyll, produce one molecule of glucose (C₆H₁₂O₆) and six molecules of oxygen (6O₂).”

However, as mentioned above, the process of Photosynthesis takes place in two stages – Light Reaction and Dark Reaction. Scroll down to know more about these stages.

Stages of Photosynthesis

There are only two photosynthesis stages; light reaction and dark reaction. Each has its own importance and a fixed role to play. Check the table below to completely understand the light dependent and light independent reactions of photosynthesis.

Word Equation for Photosynthesis, Important Questions

Q1. Photosynthesis is affected by the following factors –

1. CO₂ + Temperature + Light
2. CO₂ + Light + N₂
3. Water + Temperature + N₂
4. All of the Above

Correct Answer – a. CO₂ + Temperature + Light

Q2. Which equation shows the “reaction of photosynthesis”?

1. CO₂ + H₂O → CH₂O + O₂
2. 6CO₂ + 12H₂O → C₆H₁₂O₆ +6O₂ + 6H₂O
3. 6CO₂ + 6H₂O → C₆H₁₂O₆ +6O₂ 
4. C₆H₁₂O₆ +6O₂ → 6CO₂ + 6H₂O

Correct Answer – b. 6CO₂ + 12H₂O → C₆H₁₂O₆ +6O₂ + 6H₂O

Q3. What are the two main stages of photosynthesis? 

The two main stages of photosynthesis are the light-dependent reactions (or light reactions) and the light-independent reactions (also known as the Calvin cycle or dark reactions).

Q4. What is the role of chlorophyll in photosynthesis? 

Chlorophyll, the green pigment in plants, plays a crucial role in photosynthesis. It absorbs light energy, usually from the sun, and uses it to power the reactions involved in photosynthesis.

Q5. What are ATP and NADPH, and why are they important for photosynthesis? 

ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate) are energy-rich compounds produced during the light-dependent reactions of photosynthesis. They provide the energy needed for the Calvin cycle, the second stage of photosynthesis, where carbon dioxide is converted into glucose.

Q6. What is carbon fixation? 

Carbon fixation is a process in the Calvin cycle where carbon dioxide is incorporated into organic molecules, a crucial step in the process of photosynthesis.

Q7. What is the role of water in photosynthesis? 

Water provides the hydrogen ions needed to produce glucose and is the source of the oxygen released during photosynthesis.

Q8. What happens to the oxygen produced during photosynthesis?

The oxygen produced during photosynthesis is released into the atmosphere and is essential for the respiration of most organisms on Earth.

Q9. What is photolysis? 

Photolysis is the process in the light-dependent reactions of photosynthesis where water molecules are split, releasing oxygen, hydrogen ions, and electrons.

Q10. What is the difference between the light-dependent and light-independent reactions of photosynthesis? 

The light-dependent reactions require light energy to produce ATP and NADPH and occur in the thylakoid membranes of the chloroplasts. The light-independent reactions, also known as the Calvin cycle, use the ATP and NADPH from the light-dependent reactions to convert carbon dioxide into glucose and occur in the stroma of the chloroplasts.

That's all you should know related to the word equation of Photosynthesis. For more diverse information on Photosynthesis and its light dependent and independent reactions, check Testbook’s Biology section. Download Testbook App for quick and easy access.