Shree krishna pranami public school

Shree krishna pranami public school By-

Shubham Goel

10th A

By-

Shubham Goel

10th A

Photosynthesis

PHOTOSYNTHESIS

• It is anabolic process in which plant produces glucose as a food and o2 is liberated out a biproduct.

• Stored as carbohydrate in their bodies. 6Co2+12h2O C6H12O6+6O2+6H2O

Photosynthesis occurs in two phases

1 Light reaction

2 Dark reaction

Light Reaction

The Reaction which take place only in presence of sunlight.

Process of Light Reaction1 Entering of water into stroma from

mesophyll cell

2 Absorption of light by Thylakoids

3 Splitting of water into H+ and OH-

4 4 molecules of OH combine to form water and Oxygen which is liberated out as a biproduct.

5 The H+ reduces NADP to form NADPH to form ATP.

.

Dark reaction

The reaction which can take place in both

presence and absence of sunlight.

Process of Dark Reaction1 The CO2 enters through stomata ad

reaches to the stroma of mesophyll cell.

2 The CO2 reacts with Ribulose 1,5 bisphosphate present in stroma to form

phosphoglyceric acid.

3 In the presence of enzyme RUBP carboxylase, the PGA undergo different

Biochemical reaction with NADPH and ATP to form glucose.

Dark reaction

Mechanism of photosynthesis

1. Absorption of light by thylakoids.

2. Formation of O2 as a biproduct and Assimilatory power.

3. CO2 react with assimilatory power and goes under biochemical reactions to form glucose.

Factors responsible for rate of photosynthesis

1 CO2 - If concentration of CO2 is higher than ,rate of photosynthesis wiil increase for some time but decline

afterwards.

2 H2O- If the concentration of H2O is higherthan rate of photosynthesis will increase for some time

and decline afterwards.

3 Chlorophyll- Due to increase in amount of chlorophyll the rate of photosynthesis will only increrse and will

not come down.

4 Sunlight- The enzyme which is responsible for photosynthesis is ph. The ph enzyme work in the 25 to

35 C. and due to more heat the temperature goes above 35 C and rate of photosynthesis goes down.

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presentation