Which of the following is the key compound in the intermediary metabolism of carbohydrates, lipid and proteins

Options

A. PEP
B. PGA
C. Acetyl CoA
D. ?-ketoglutarate

Answer

**Step-by-Step Solution:**

1. **Identify the Key Compounds**: The question asks for the key compound involved in the intermediary metabolism of carbohydrates, lipids, and proteins.

2. **Understand the Metabolism of Carbohydrates**: Carbohydrates, primarily glucose, undergo glycolysis to form pyruvate. Pyruvate is then converted into Acetyl Coenzyme A (Acetyl CoA).

3. **Examine the Metabolism of Lipids**: Lipids are broken down into glycerol and fatty acids. Glycerol can be converted into Acetyl CoA, while fatty acids undergo beta-oxidation to also produce Acetyl CoA.

4. **Analyze the Metabolism of Proteins**: Proteins are made up of amino acids. During the process of deamination, amino acids are converted into intermediates such as pyruvate, which can then be converted into Acetyl CoA.

5. **Conclude the Common Intermediate**: Since Acetyl CoA is produced from the metabolism of carbohydrates (from pyruvate), lipids (from glycerol and fatty acids), and proteins (from deaminated amino acids), it serves as a key compound in the intermediary metabolism of all three macromolecules.

6. **Final Answer**: The key compound in the intermediary metabolism of carbohydrates, lipids, and proteins is **Acetyl Coenzyme A**.

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