BiomoleculesMedium
Question
Identify the step in tricarboxylic acid cycle, which does not involve oxidation of substrate.
Options
A.Succinyl-CoA → Succinic acid
B.Isocitrate → $\alpha$-ketoglutaric acid
C.Malic acid → Oxaloacetic acid
D.Succinic acid → Malic acid
Solution
Sol. [Key Concept: Nonoxidative step in the TCA cycle]
Succinyl-CoA is converted to succinate by succinyl-CoA synthetase with substrate level phosphorylation, producing GTP or ATP. No oxidation of the substrate occurs in this step. Isocitrate to α-ketoglutarate and malate to oxaloacetate involve oxidation; succinate to malate includes succinate oxidation to fumarate. Hence, option (1).
Create a free account to view solution
View Solution Free