Select the incorrect statement about functions of Zn in orgainsms:

Options

A. it regulate alcohol dehydrogenase
B. It regulates carbonic anhydrase
C. It help tryptophan synthesis
D. It protects the plant against fungal attack

Answer

To determine the incorrect statement about the functions of zinc (Zn) in organisms, we will analyze each statement provided in the question step by step.

### Step-by-Step Solution:

1. **Statement 1: "It regulates the alcohol dehydrogenase."**
- **Analysis:** Alcohol dehydrogenase is an enzyme that requires zinc as a cofactor. Zinc plays a crucial role in the function of this enzyme, which is involved in the metabolism of alcohol.
- **Conclusion:** This statement is **correct**.

2. **Statement 2: "It regulates carbonic anhydrase."**
- **Analysis:** Carbonic anhydrase is another enzyme that contains zinc at its active site. It is classified as a metalloenzyme due to the presence of zinc, which is essential for its activity in maintaining acid-base balance and facilitating the transport of carbon dioxide.
- **Conclusion:** This statement is **correct**.

3. **Statement 3: "It helps in tryptophan synthesis."**
- **Analysis:** Tryptophan is an essential amino acid, and zinc is known to act as a cofactor in the synthesis of this amino acid in plants. Therefore, zinc is indeed involved in tryptophan synthesis.
- **Conclusion:** This statement is **correct**.

4. **Statement 4: "It protects the plant against fungal attack."**
- **Analysis:** While zinc does play a role in plant defense mechanisms and helps in managing oxidative stress, there is no substantial evidence to support the claim that zinc directly protects plants from fungal attacks. This statement lacks scientific backing.
- **Conclusion:** This statement is **incorrect**.

### Final Answer:
The incorrect statement about the functions of zinc in organisms is: **"It protects the plant against fungal attack."**

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