The intermediate product between `alpha`-ketoglutaric acid and succinic acid in TCA cycle is

Options

A. acetyl CoA
B. succinly CoA
C. fumarate
D. oxalosuccinic acid

Answer

To find the intermediate product between alpha-ketoglutaric acid and succinic acid in the TCA cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the TCA Cycle**: The TCA cycle, also known as the Krebs cycle, is a series of chemical reactions used by aerobic organisms to generate energy through the oxidation of acetyl-CoA.

2. **Identify the Relevant Compounds**: We need to focus on the compounds mentioned in the question: alpha-ketoglutaric acid and succinic acid.

3. **Locate the Position of the Compounds in the Cycle**: In the TCA cycle, alpha-ketoglutaric acid (also known as 2-oxoglutarate) is converted into succinic acid through a series of reactions.

4. **Identify the Intermediate Product**: The conversion from alpha-ketoglutaric acid to succinic acid involves the formation of an intermediate product. This intermediate product is known as succinyl coenzyme A (succinyl-CoA).

5. **Understand the Reaction**: During the conversion, one molecule of carbon dioxide (CO2) is released, and NAD+ is reduced to NADH. The overall reaction can be summarized as:
- Alpha-ketoglutaric acid → Succinyl-CoA + CO2 + NADH

6. **Final Answer**: Therefore, the intermediate product between alpha-ketoglutaric acid and succinic acid in the TCA cycle is succinyl coenzyme A.