Which of the following metabolites is commonly produced during the breakdown of fats , Carbohydrates, and proteins ?

Options

A. Glucose 6 - phosphate
B. Fructose 1,6 -bisphosphate
C. Pyruvic acid
D. Acetyl-CoA

Answer

To solve the question "Which of the following metabolites is commonly produced during the breakdown of fats, carbohydrates, and proteins?", we will analyze the metabolic pathways involved in the breakdown of each of these macromolecules.

### Step-by-Step Solution:

1. **Understanding the Breakdown of Carbohydrates**:
- Carbohydrates are primarily broken down into glucose.
- Glucose then undergoes glycolysis, a process that converts glucose into pyruvic acid.

2. **Conversion of Pyruvic Acid**:
- Pyruvic acid can then be converted into acetyl coenzyme A (acetyl-CoA) before entering the Krebs cycle (also known as the citric acid cycle).

3. **Understanding the Breakdown of Fats**:
- Fats are broken down into fatty acids and glycerol.
- Fatty acids undergo beta-oxidation, which converts them into acetyl coenzyme A.

4. **Understanding the Breakdown of Proteins**:
- Proteins are broken down into amino acids.
- Amino acids can be converted into various intermediates, including pyruvic acid or directly into acetyl coenzyme A, depending on the specific amino acid.

5. **Common Metabolite**:
- After analyzing the breakdown pathways, we find that both carbohydrates and fats directly produce acetyl coenzyme A.
- Amino acids can also be converted into pyruvic acid, which is then converted into acetyl coenzyme A.

6. **Conclusion**:
- The common metabolite produced during the breakdown of fats, carbohydrates, and proteins is **acetyl coenzyme A**.

### Final Answer:
**D. Acetyl coenzyme A**

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