From the oxidation of one molecule of palmitic acid (fatty acid), the number of ATP molecules gained are

Options

A. 129 ATP
B. 132 ATP
C. 36 ATP
D. 76 ATP

Answer

To determine the number of ATP molecules gained from the oxidation of one molecule of palmitic acid (a fatty acid), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of Palmitic Acid**:
- Palmitic acid is a saturated fatty acid with 16 carbon atoms (C16H32O2).

2. **Understand Beta-Oxidation**:
- Beta-oxidation is the process by which fatty acids are broken down in the mitochondria to produce acetyl-CoA, NADH, and FADH2.

3. **Calculate the Number of Acetyl-CoA Produced**:
- Each cycle of beta-oxidation cleaves off a 2-carbon acetyl-CoA unit.
- For palmitic acid (16 carbons), the number of acetyl-CoA produced is:
\[ \text{Number of Acetyl-CoA} = \frac{16}{2} = 8 \]

4. **Determine the Number of Beta-Oxidation Cycles**:
- The number of cycles required to produce 8 acetyl-CoA is:
\[ \text{Number of Cycles} = 8 - 1 = 7 \]

5. **Calculate NADH and FADH2 Production**:
- Each cycle of beta-oxidation produces 1 NADH and 1 FADH2.
- Therefore, from 7 cycles:
\[ \text{NADH} = 7 \quad \text{and} \quad \text{FADH2} = 7 \]

6. **ATP Yield from NADH and FADH2**:
- Each NADH produces 3 ATP during oxidative phosphorylation:
\[ \text{ATP from NADH} = 7 \times 3 = 21 \]
- Each FADH2 produces 2 ATP:
\[ \text{ATP from FADH2} = 7 \times 2 = 14 \]

7. **ATP Yield from Acetyl-CoA**:
- Each acetyl-CoA produces 12 ATP in the Krebs cycle:
\[ \text{ATP from Acetyl-CoA} = 8 \times 12 = 96 \]

8. **Total ATP Calculation Before Activation**:
- Sum the ATP produced from NADH, FADH2, and acetyl-CoA:
\[ \text{Total ATP} = 21 + 14 + 96 = 131 \]

9. **Account for Activation Energy**:
- The activation of palmitic acid requires 2 ATP, which must be subtracted from the total:
\[ \text{Final ATP Yield} = 131 - 2 = 129 \]

### Final Answer:
The total number of ATP molecules gained from the oxidation of one molecule of palmitic acid is **129 ATP**.

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