The dicarboxylic acid required for the formation of first Tricarboxylic acid of Krebs cycle

Options

A. a Ketoglutaric acid
B. Oxalosuccinic acid
C. Malic acid
D. Oxaloacetic acid

Answer

To determine the dicarboxylic acid required for the formation of the first tricarboxylic acid in the Krebs cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Krebs Cycle**: The Krebs cycle, also known as the citric acid cycle or TCA cycle, is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats, and proteins.

2. **Identifying the Starting Compound**: The cycle begins with a 4-carbon compound called oxaloacetic acid (OAA). This compound is crucial as it combines with acetyl-CoA to initiate the cycle.

3. **Formation of the First Tricarboxylic Acid**: When oxaloacetic acid combines with acetyl-CoA, it forms citric acid (also known as citrate), which is a 6-carbon tricarboxylic acid. This is the first tricarboxylic acid produced in the Krebs cycle.

4. **Conclusion**: The dicarboxylic acid required for the formation of the first tricarboxylic acid (citric acid) is oxaloacetic acid.

### Final Answer:
The dicarboxylic acid required for the formation of the first tricarboxylic acid of the Krebs cycle is **oxaloacetic acid**.

---