Ques. 1NEET 2017
Which statement is wrong for Krebs' cycle?
- There is one point in the cycle where FAD+ is reduced to FADH2.
- During conversion of succinyl CoA to succinic acid, a molecule of GTP is synthesised.
- The cycle starts with condensation of acetyl group (acetyl CoA) with pyruvic acid to yield citric acid.
- There are three points in the cycle where NAD+ is reduced to NADH + H+.
Answer
(3) The cycle starts with condensation of acetyl group (acetyl CoA) with pyruvic acid to yield citric acid.
Solution
As per NCERT, the TCA cycle starts with the condensation of the acetyl group (acetyl CoA) with oxaloacetic acid (OAA) and water to yield citric acid.
∴ Statement (3), which says 'with pyruvic acid', is wrong.
(1), (2) and (4) are as given in NCERT: one point where FAD+ → FADH2, GTP formed at succinyl CoA → succinic acid, three points where NAD+ → NADH + H+.
Answer: (3)