Respiratory enzymes occur in bacterium in

Options

A. Plasma membrane
B. Mitochondria
C. Golgi apparatus
D. E.R.

Answer

To answer the question "Respiratory enzymes occur in bacterium in:", we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks where respiratory enzymes are located in bacteria.

2. **Identify the Options**: The options provided are:
- a. Plasma membrane
- b. Mitochondria
- c. Golgi apparatus
- d. Endoplasmic reticulum (ER)

3. **Recall Bacterial Cell Structure**: Bacteria are prokaryotic organisms, meaning they do not have membrane-bound organelles like mitochondria, Golgi apparatus, or endoplasmic reticulum.

4. **Consider the Role of Mesosomes**: In bacteria, structures called mesosomes (which are invaginations of the plasma membrane) increase the surface area for various functions, including respiration.

5. **Locate Respiratory Enzymes**: Since bacteria do not have mitochondria, the respiratory enzymes are located in the plasma membrane (or cell membrane).

6. **Select the Correct Answer**: Based on the understanding that respiratory enzymes are found in the plasma membrane of bacteria, the correct answer is option A: Plasma membrane.

### Final Answer:
The respiratory enzymes occur in bacterium in **a. Plasma membrane**.

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