Enzyme present in limited quantity in Asians for metabolism of alcohol is

Options

A. Alcohol dehydrogenase
B. Succinate thiokinase
C. Acetaldehyde dehydrogenase
D. Both A and B

Answer

To solve the question regarding the enzyme present in limited quantity in Asians for the metabolism of alcohol, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the specific enzyme that is present in limited quantities in Asians, which is involved in the metabolism of alcohol.

2. **Identify the Enzymes**: The options provided are:
- A) Alcohol dehydrogenase
- B) Succinate thiophainase
- C) Acetaldehyde dehydrogenase
- D) Both A and B

3. **Review Alcohol Metabolism**:
- Alcohol is primarily metabolized in the liver.
- The first step involves the conversion of alcohol to acetaldehyde by the enzyme **alcohol dehydrogenase (ADH)**.
- The next step involves the conversion of acetaldehyde to acetate by the enzyme **acetaldehyde dehydrogenase (ALDH)**.

4. **Focus on Limited Quantity**:
- It is known that a significant percentage of individuals from Northeast Asia have a mutation in the gene responsible for producing acetaldehyde dehydrogenase (ALDH). This mutation leads to decreased activity of this enzyme, resulting in limited quantities of ALDH in these individuals.

5. **Eliminate Incorrect Options**:
- Since both alcohol dehydrogenase and succinate thiophainase are not known to be limited in quantity in Asians, we can eliminate options A and B.
- Therefore, the correct answer must be **C) Acetaldehyde dehydrogenase**.

6. **Final Answer**: The enzyme present in limited quantity in Asians for metabolism of alcohol is **Acetaldehyde dehydrogenase (ALDH)**.