`P_(450)` and `P_(448)` occurs over

Options

A. S.E.R
B. R.E.R
C. Annulate E.R
D. Transitional E.R

Answer

To answer the question regarding where P450 and P448 occur, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding Cytochromes**:
- Cytochrome P450 and P448 are types of cytochromes, which are proteins that play a crucial role in various biochemical processes, particularly in the metabolism of drugs and detoxification of harmful substances.

2. **Function of Cytochrome P450 and P448**:
- These cytochromes act as enzymes that help in detoxifying the body by metabolizing toxic substances and carcinogenic compounds (substances that can cause cancer).

3. **Location of Cytochrome P450 and P448**:
- The primary site for the action of cytochrome P450 and P448 is the liver, which is the main organ responsible for detoxification in the body.

4. **Cellular Structure Involved**:
- Cytochrome P450 and P448 are located in the Smooth Endoplasmic Reticulum (SER). The SER is involved in lipid synthesis and detoxification processes.

5. **Exclusion of Other Structures**:
- It is important to note that these processes do not occur in the Rough Endoplasmic Reticulum (RER), annulate ER, or transitional ER. The SER is specifically adapted for these functions.

6. **Conclusion**:
- Therefore, the correct answer to the question is that P450 and P448 occur in the Smooth Endoplasmic Reticulum (SER).

### Final Answer:
Cytochrome P450 and P448 occur in the Smooth Endoplasmic Reticulum (SER).

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