How many `NADH_(2)` are produced per cucle of TCA cycle

Options

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

Answer

To determine how many NADH2 molecules are produced per cycle of the TCA cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the TCA Cycle**: The TCA cycle, also known as the Citric Acid Cycle or Krebs Cycle, is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl-CoA.

2. **Identify the Starting Point**: The cycle begins with the condensation of Acetyl-CoA and Oxaloacetate to form Citrate.

3. **Identify Key Steps in the Cycle**: As the cycle progresses, several key reactions occur where NADH is produced.

4. **Count the NADH Production**:
- **First Step**: Isocitrate is converted to Alpha-Ketoglutarate, producing one NADH.
- **Second Step**: Alpha-Ketoglutarate is converted to Succinyl-CoA, producing another NADH.
- **Third Step**: Malate is converted back to Oxaloacetate, producing a third NADH.

5. **Total NADH Production**: By adding the NADH produced from these three steps, we find that a total of **3 NADH** molecules are produced in one complete cycle of the TCA cycle.

### Final Answer:
**3 NADH are produced per cycle of the TCA cycle.**

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