Question

Arrange the following compound formed in respiration based on their C-atoms in ascending order.
(I) Pyruvic acid (II) $\alpha$-ketoglutaric acid (III) Citric acid (IV) Malic acid

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

Answer 1

The correct option is B I, IV, II, III

Pyruvic acid is a three-carbon compound with empirical formula C${}_3$H${}_4$O${}_3$.

Alpha-ketoglutaric acid is a five-carbon compound with empirical formula C${}_5$H${}_6$O${}_5$.

Citric acid is a six-carbon compound with empirical formula C${}_6$H${}_8$O${}_7$.

Malic acid is a four-carbon compound with empirical formula C${}_4$H${}_4$O${}_4$.

Thus, the ascending order of these molecules on the basis of a number of carbon atoms will be pyruvic acid, malic acid, alpha-ketoglutaric acid and citric acid.

Thus, the correct answer is option B.