Which of the following enzymes is involved in fermentation ?

Options

A. Pyruvate dehydrogenase
B. Pyruvic acid decarboxylase
C. Succinate dehydrogenase
D. Citrate dehydrogenase

Answer

To answer the question regarding which enzyme is involved in fermentation, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Fermentation**:
- Fermentation is an anaerobic process that breaks down glucose or other organic nutrients to produce energy in the form of ATP. It occurs in the absence of oxygen.

2. **Identifying the Process**:
- During fermentation, glucose is first converted into pyruvic acid (pyruvate). This is a crucial step in both alcoholic fermentation and lactic acid fermentation.

3. **Alcoholic Fermentation**:
- In alcoholic fermentation, pyruvic acid is converted into acetaldehyde. This conversion is facilitated by the enzyme **pyruvate decarboxylase**.

4. **Conversion to Ethanol**:
- The acetaldehyde produced is then converted into ethanol by the enzyme **alcohol dehydrogenase**.

5. **Analyzing the Options**:
- Now, looking at the given options:
- **Pyruvate dehydrogenase**: Involved in aerobic respiration, not fermentation.
- **Pyruvic acid dehydrogenase**: Not a standard term; likely refers to pyruvate dehydrogenase.
- **Carboxylase**: Generally involved in carboxylation reactions, not fermentation.
- **Succinate dehydrogenase**: Involved in the citric acid cycle, not fermentation.
- **Citrate dehydrogenase**: Also involved in the citric acid cycle, not fermentation.

6. **Conclusion**:
- The enzyme specifically involved in fermentation is **pyruvate decarboxylase**. This enzyme catalyzes the conversion of pyruvic acid to acetaldehyde, which is a key step in alcoholic fermentation.

### Final Answer:
The enzyme involved in fermentation is **pyruvate decarboxylase**.

---