Question

Reduction (Step 2 of Calvin Cycle) occurs in 2 steps:

a) Reduction of PGA to G3P
b) Reduction of G3P to RuBP
c) Reduction of PGA to RuBP
d) Reduction of RuBP to G3P

Answer 1

The correct step in the reduction phase of the Calvin Cycle is the reduction of PGA to G3P using electrons supplied by NADPH, making (a) the right answer.

Step-by-step explanation:

The student's question refers to step 2 of the Calvin Cycle, which is the reduction phase. During this stage, 3-phosphoglycerate (3-PGA) undergoes a two-step process to be reduced to glyceraldehyde 3-phosphate (G3P).

The correct sequence in the reduction phase of the Calvin Cycle is as follows:

1. Reduction of PGA to G3P using electrons supplied by NADPH.
2. Conversion of G3P into RuBP is not part of the reduction phase; instead, it occurs in the subsequent regeneration phase of the cycle.

Therefore, the correct answer to the student's question is:
a) Reduction of PGA to G3P. This reduction involves ATP and NADPH, and is essential for the production of carbohydrate molecules from G3P.