¶¶¶Photosynthesis is a biological process used by all green plants to prepare food with the help of sunlight water and carbon dioxide. The word photosynthesis is derived from the Greek word “Photo” meaning light and “Synthesis” meaning connecting together. This means combining together with the help of light energy.

This biological process is also used by algae and several bacteria to convert solar energy into chemical energy. Oxygen is liberated as a by-product, and light is considered as the major factor to complete the process of photosynthesis. This process occurs usually when plants use light energy to convert carbon dioxide and water into glucose and oxygen gas. Leaves are made up of small cells which have a tiny structure known as chloroplasts. Each chloroplast contains a green coloured pigment called chlorophyll. Light energy is absorbed by chlorophyll molecules whereas carbon dioxide (CO2) and oxygen (O2) enter through the tiny pores of stomata located in the epidermis of leaves.

Oxygen is considered one of the most important by-products of this process on which most of the living organism depend upon. Glucose/Sugar is a form of carbohydrates that are processed during the process of photosynthesis. It is commonly used by green plants in the form of an energy source to produce leaves, fruits, flowers, and seeds. The glucose molecules then combine with each other to develop more complex carbohydrates like cellulose and starch. The cellulose is considered as the structural material that is used in plant cell walls. The overall reaction of photosynthesis process is:

6CO2 + 6H2O —> C6H12O6 + 6O2...

Photosynthesis is a biological process by which green plants and some other organisms use sunlight to synthesize foods with the help of carbon dioxide and water. This process is vital for the existence of life on earth as it produces oxygen which is necessary for respiration.



Photosynthesis can be divided into two stages:

1. Light-dependent reactions: These reactions occur in the thylakoid membrane of chloroplasts. Chlorophyll absorbs sunlight and converts it into chemical energy in the form of ATP and NADPH. Water is also split into oxygen and hydrogen ions in this stage.


2. Light-independent reactions: Also known as the Calvin cycle, these reactions occur in the stroma of chloroplasts. Carbon dioxide is fixed into glucose using the energy from ATP and NADPH produced in the light-dependent reactions.

Light-dependent reactions occur in the thylakoid membrane of chloroplasts. They can be summarized as follows:

1. Chlorophyll absorbs sunlight and converts it into chemical energy in the form of ATP and NADPH.


2. Water is split into oxygen and hydrogen ions using the energy from the absorbed sunlight. The oxygen is released into the atmosphere as a byproduct.


3. The hydrogen ions are used to create a proton gradient across the thylakoid membrane. This gradient is used to generate ATP through a process called chemiosmosis.


4. The ATP and NADPH are used in the light-independent reactions to convert carbon dioxide into glucose.

Light-independent reactions occur in the stroma of chloroplasts. They can be summarized as follows:

1. Carbon dioxide is fixed into glucose using the energy from ATP and NADPH produced in the light-dependent reactions.


2. The carbon dioxide is initially combined with a 5-carbon sugar molecule called ribulose bisphosphate (RuBP) to form an unstable 6-carbon molecule.


3. The unstable 6-carbon molecule is quickly broken down into two 3-carbon molecules called 3-phosphoglycerate (3-PGA).


4. The 3-PGA molecules are then used in a series of reactions to create glucose.

Photosynthesis is a complex process that is essential for the survival of life on earth. It involves two stages: the light-dependent reactions and the light-independent reactions. The light-dependent reactions occur in the thylakoid membrane of chloroplasts and produce ATP and NADPH using energy from the sun. The light-independent reactions occur in the stroma of chloroplasts and use the energy from ATP and NADPH to convert carbon dioxide into glucose.