Intermediate common to proteins and carbohydrate oxidation is

Options

A. Pyruvate
B. Glycerol
C. Oxaloacetate
D. Succinate

Answer

To solve the question "Intermediate common to proteins and carbohydrate oxidation is:", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Carbohydrate Oxidation**:
- Carbohydrates, particularly glucose, undergo glycolysis where glucose (a 6-carbon compound) is broken down.
- The process begins with glucose being converted into glucose-6-phosphate, then into fructose-6-phosphate, and subsequently into fructose-1,6-bisphosphate.
- This compound is split into two 3-carbon molecules: dihydroxyacetone phosphate and glyceraldehyde-3-phosphate.
- Glyceraldehyde-3-phosphate is then converted into pyruvate (pyruvic acid).

2. **Understanding Protein Oxidation**:
- Proteins are broken down into amino acids.
- These amino acids undergo a process called deamination, where the amino group is removed.
- The remaining carbon skeletons of these amino acids can be converted into pyruvate or other intermediates depending on the specific amino acid.

3. **Identifying the Common Intermediate**:
- Both carbohydrate oxidation (specifically glucose) and protein oxidation (after deamination of amino acids) lead to the formation of pyruvate.
- Pyruvate then enters the Krebs cycle (also known as the citric acid cycle) after being converted into acetyl-CoA.

4. **Conclusion**:
- Therefore, the common intermediate in the oxidation of both proteins and carbohydrates is **pyruvate**.

### Final Answer:
The intermediate common to proteins and carbohydrate oxidation is **pyruvate**.

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