NEETBotanyPhotosynthesis in Higher Plants
In the Calvin cycle, the assimilatory power (ATP and NADPH) generated during the light reaction is consumed. Identify the correct statement regarding their utilization in the different stages of the cycle:
Options
- AATP is consumed during carboxylation and reduction, whereas NADPH is consumed only during reduction.
- BATP is consumed during reduction and regeneration, whereas NADPH is consumed only during reduction.
- CBoth ATP and NADPH are consumed during the reduction and regeneration stages.
- DATP is consumed only during reduction, whereas NADPH is consumed during both reduction and regeneration.
Correct answer
B. ATP is consumed during reduction and regeneration, whereas NADPH is consumed only during reduction.
Step-by-step solution
The Calvin cycle (biosynthetic phase) consists of three main stages: carboxylation, reduction, and regeneration. 1. Carboxylation is the fixation of CO ₂ into a stable organic intermediate (3-PGA). This step does not consume ATP or NADPH. 2. Reduction involves a series of reactions that lead to the formation of glucose. This step utilizes both ATP (for phosphorylation) and NADPH (for reduction). 3. Regeneration is the crucial step of reforming the CO ₂ acceptor molecule RuBP, which requires one molecule of ATP for