How many carbon atoms are present in Acetyl CoA ?

Options

A. 2
B. 6
C. 4
D. 3

Answer

To determine how many carbon atoms are present in Acetyl CoA, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Formation of Acetyl CoA**:
- Acetyl CoA is formed during cellular respiration, specifically after glycolysis.
- Glycolysis converts glucose into pyruvic acid, which is a 3-carbon compound.

2. **Decarboxylation of Pyruvic Acid**:
- Pyruvic acid (3 carbons) undergoes a process called oxidative decarboxylation.
- During this process, one carbon atom is removed from pyruvic acid in the form of carbon dioxide (CO₂).

3. **Formation of Acetyl**:
- After the removal of one carbon atom, the remaining structure is a 2-carbon compound known as acetyl.

4. **Attachment of Coenzyme A**:
- The acetyl group (2 carbons) then combines with coenzyme A (CoA) to form Acetyl CoA.
- Coenzyme A does not contribute any additional carbon atoms to the structure of Acetyl CoA.

5. **Conclusion**:
- Therefore, Acetyl CoA contains a total of **2 carbon atoms**.

### Final Answer:
Acetyl CoA contains **2 carbon atoms**.

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