What is sequence of steps in photosynthesis? How is it different in desert plants and those in temprate regions?
Photosynthesis is the process by which chlorophyll-containing cells synthesize food in the form of carbohydrates, carbon dioxide, and water using sunlight.
Therefore, the raw materials required for photosynthesis are CO2 and H2O and the products formed are carbohydrates and O2.
Hence, the process can be represented as:
The sequence of steps in photosynthesis are light reactions and the dark reactions .
Light reactions – This reaction takes place in the presence of light. The chlorophyll molecules absorb the light energy This light energy splits the water molecules into hydrogen and oxygen.In this reaction ATP and NADPH 2 are produced. Light reactions take place in the membranes of thylakoids.
Dark reaction - This reaction does not require direct light and occurs in the stroma of chloroplasts. In this phase the ATP and NADPH 2 that were formed during light reactions get utilized for the reduction of CO2 to carbohydrates.
The steps of photosynthesis are mostly the same for both the plants of desert and temperate regions. The only difference is that desert plants take up carbon dioxide at night and store it as an organic acid inside the body. In the day time to avoid excess transpiration due to scorching heat they keep their stomata closed and use the stored carbon dioxide by breaking down the organic acid. This mechanism is known as CAM (Crassulacean Acid Metabolism).