Question

Give an account of Calvin cycle

Answer 1

The Calvin cycle is part of photosynthesis, which occurs in two stages. In the first stage, chemical reactions use energy from light to produce ATP and NADPH. In the second stage (Calvin cycle or dark reactions), carbon dioxide and water are converted into organic molecules, such as glucose.

Answer 2

Calvin Cycle

Calvin and his co-workers formulated the complete metabolic pathway of carbon assimilation in the form of a cycle. The Calvin cycle is a set of reactions that occur during the light independent phase of photosynthesis in order to convert carbon dioxide into glucose.

The Calvin Cycle has three stages :

1. Carboxylation
2. Reduction
3. Regeneration

Carboxylation - It is the most important step of the Calvin cycle where CO$_2$ is used for the carboxylation of RuBP in the presence of enzyme RuBisCO which results in the formation of 3-PGA.

Reduction - During this stage, Carbohydrate is formed by utilising two molecules of ATP and NADPH for reduction per CO$_2$ fixed.

Regeneration - In this stage, The CO$_2$ acceptor RuBP is formed again so that the cycle continues.