NEET2026BiologyChapterActual
Given below are two statements regarding the biosynthetic phase of photosynthesis: Statement I: During the reduction step of the Calvin cycle, 2 molecules of ATP and 2 molecules of NADPH are utilized for every molecule of CO ₂ fixed. Statement II: The regeneration of the primary CO ₂ acceptor requires 1 molecule of ATP and 1 molecule of NADPH to maintain the uninterrupted operation of the cycle. In the light of the a
Options
- ABoth Statement I and Statement II are correct
- BStatement I is incorrect but Statement II is correct
- CBoth Statement I and Statement II are incorrect
- DStatement I is correct but Statement II is incorrect
Correct answer
D. Statement I is correct but Statement II is incorrect
Step-by-step solution
Statement I is correct because during the reduction step of the Calvin cycle, the conversion of two molecules of 3-phosphoglycerate (3-PGA) into triose phosphate requires 2 molecules of ATP for phosphorylation and 2 molecules of NADPH for reduction per molecule of CO ₂ fixed. Statement II is incorrect because the regeneration of the primary CO ₂ acceptor (RuBP) requires only 1 molecule of ATP for phosphorylation per molecule of CO ₂ fixed. It does not require NADPH. Therefore, Statement I is correct but Statement I