Question

Arrange the intermediate compounds of RUBP regeneration in correct sequence:

I. Ribulose-5-Phosphate
II. Erythrose-4-Phosphate
III. Fructose-6-Phosphate
IV. Sedoheptulose-7-Phosphate
V. Ribose-5-Phosphate
VI. Fructose-1,6-Bisphosphate

• A. I, V, IV, VI, II, III
• B. II, VI, III, IV, V, I
• C. III, II, VI, IV, V, I
• D. VI, III, II, IV, V, I

Hint:

Know Calvin cycle intermediates: Fructose-1,6-BP → F-6-P → rearrangements → Ribulose-5-P → RUBP.

Answer 1

The Correct Option is D

RUBP regeneration sequence:

(1) VI. Fructose 1,6-bisphosphate (initial product from Calvin cycle)

(2) III. Fructose 6-phosphate (formed after dephosphorylation)

(3) II. Erythrose 4-phosphate (via rearrangements)

(4) IV. Sedoheptulose 7-phosphate (formed through transaldolase action)

(5) V. Ribose 5-phosphate (via carbon rearrangements)

(6) I. Ribulose 5-phosphate (precursor to RUBP)