NEETBotanyPhotosynthesis in Higher Plants
Match List-I with List-II regarding the energy requirements in the Calvin cycle. List-I List-II (A) Reduction phase per CO ₂ fixed (I) 18 ATP + 12 NADPH (B) Regeneration phase per CO ₂ fixed (II) 3 ATP + 2 NADPH (C) Total requirement per CO ₂ fixed (III) 1 ATP + 0 NADPH (D) Total requirement for one glucose molecule (IV) 2 ATP + 2 NADPH Choose the correct answer from the options given below:
Options
- A(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
- B(A)-(IV), (B)-(II), (C)-(III), (D)-(I)
- C(A)-(II), (B)-(III), (C)-(IV), (D)-(I)
- D(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
Correct answer
A. (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
Step-by-step solution
In the Calvin cycle, the reduction of one molecule of CO ₂ requires 2 ATP and 2 NADPH . The regeneration of the primary CO ₂ acceptor (RuBP) requires 1 ATP per CO ₂ fixed, and no NADPH . Therefore, the total energy requirement for the fixation of one CO ₂ molecule is 3 ATP and 2 NADPH . To synthesise one molecule of glucose, six turns of the cycle are required, which means 6 3 = 18 ATP and 6 2 = 12 NADPH are consumed. Answer: (A)-(IV), (B)-(III), (C)-(II), (D)-(I)