Question

During Krebs cycle, the intermediate $\alpha$-ketoglutarate is formed as a result of ______________.

• A. hydration of oxalosuccinate
• B. oxidation of succinyl co-A
• C. oxidation of cis-aconitate
• D. decarboxylation of oxalosuccinate

Hint:

Decarboxylation reactions in Krebs cycle release CO$_2$.

Answer 1

The Correct Option is D

Step 1: Understanding Krebs cycle.
Krebs cycle is a cyclic series of enzyme-controlled reactions involved in aerobic respiration.
Step 2: Formation of $\alpha$-ketoglutarate.
Isocitrate is first oxidized to oxalosuccinate.
Oxalosuccinate then undergoes decarboxylation to form $\alpha$-ketoglutarate.
Step 3: Identifying the correct process.
The key step forming $\alpha$-ketoglutarate is decarboxylation of oxalosuccinate.
Step 4: Conclusion.
Hence, $\alpha$-ketoglutarate is formed by decarboxylation of oxalosuccinate.