Q48 / 200 · MHT CET - Medical 2026 (24 April Shift 2) · Biology
In Krebs' cycle, GTP is produced during the conversion of ___.
- A$\alpha$-ketoglutarate to succinyl CoA.
- Bfumarate to malate.
- Csuccinate to fumarate.
- Correct answerDsuccinyl CoA to succinic acid.
Solution
In the Krebs cycle, the conversion of succinyl CoA to succinic acid is catalyzed by the enzyme succinyl-CoA synthetase.
During this reaction, the cleavage of the high-energy thioester bond of succinyl CoA releases energy, which is used to phosphorylate a molecule of GDP to GTP. This process is an example of substrate-level phosphorylation.
The GTP produced can subsequently transfer its terminal phosphate group to ADP to form ATP.
Therefore, GTP is produced during the conversion of succinyl CoA to succinic acid.
Answer: succinyl CoA to succinic acid.
During this reaction, the cleavage of the high-energy thioester bond of succinyl CoA releases energy, which is used to phosphorylate a molecule of GDP to GTP. This process is an example of substrate-level phosphorylation.
The GTP produced can subsequently transfer its terminal phosphate group to ADP to form ATP.
Therefore, GTP is produced during the conversion of succinyl CoA to succinic acid.
Answer: succinyl CoA to succinic acid.
Hence, the correct answer is option: 'D'.