In alcoholic fermentation by yeasts, the `NADH_2` produced during glycolysis is used to reduce

Options

A. Acetaldehyde to ethanol
B. NADP to` NADPH_2`
C. Pyruvic acid to lactic acid
D. Lactic acid to pyrvic acid

Answer

### Step-by-Step Solution:

1. **Understanding the Process of Alcoholic Fermentation**:
- Alcoholic fermentation is a process that occurs in yeast under anaerobic (absence of oxygen) conditions. It involves the conversion of glucose into ethanol and carbon dioxide.

2. **Glycolysis**:
- The first step in fermentation is glycolysis, where one molecule of glucose is broken down into two molecules of pyruvate. During this process, two molecules of NADH (reduced form of NAD+) are produced and two ATP molecules are generated.

3. **Conversion of Pyruvate**:
- After glycolysis, in the absence of oxygen, pyruvate undergoes further transformation. The pyruvate is first converted into acetaldehyde, releasing carbon dioxide in the process.

4. **Reduction of Acetaldehyde**:
- The next step involves the reduction of acetaldehyde to ethanol. This is where the NADH produced during glycolysis comes into play. The NADH donates electrons to acetaldehyde, reducing it to ethanol.

5. **Final Reaction**:
- The overall reaction can be summarized as:
- Glucose → 2 Pyruvate → 2 Acetaldehyde + 2 CO₂ → 2 Ethanol
- During the conversion of acetaldehyde to ethanol, NADH is oxidized back to NAD+, which is essential for glycolysis to continue.

6. **Conclusion**:
- Thus, in alcoholic fermentation by yeasts, the NADH produced during glycolysis is used to reduce acetaldehyde to ethanol.

### Final Answer:
- The correct answer is **acetaldehyde to ethanol**.