The peripheral proteins found in fluid mosaic model of membrane are

Options

A. superficially attached
B. embedded in lipid layer
C. seen projecting beyond lipid layers
D. seen floating in and out of the membrane

Answer

### Step-by-Step Solution:

1. **Understanding the Fluid Mosaic Model**: The fluid mosaic model, proposed by Singer and Nicholson, describes the structure of the cell membrane. It consists of a phospholipid bilayer with proteins embedded or attached to it.

2. **Types of Membrane Proteins**: There are two main types of proteins associated with the cell membrane:
- **Integral Proteins**: These proteins are embedded within the lipid bilayer and can span across the membrane.
- **Peripheral Proteins**: These proteins are not embedded in the lipid bilayer but are attached to the exterior or interior surfaces of the membrane.

3. **Identifying Peripheral Proteins**: The question asks about the characteristics of peripheral proteins in the fluid mosaic model.
- Peripheral proteins are typically **superficially attached** to the membrane, meaning they are loosely associated with the lipid bilayer and can be removed more easily than integral proteins.

4. **Evaluating the Options**:
- **Option A: Superficially attached** - This is correct as peripheral proteins are indeed superficially attached to the membrane.
- **Option B: Embedded in lipid layer** - This is incorrect; this describes integral proteins, not peripheral proteins.
- **Option C: Seen projecting beyond the lipid layer** - This is also incorrect; peripheral proteins do not project beyond the lipid layer but are attached to it.
- **Option D: Seen floating in and out of the membrane** - This is incorrect; peripheral proteins are not floating but are attached to the membrane.

5. **Conclusion**: Based on the evaluation of the options, the correct answer is that peripheral proteins are **superficially attached** to the membrane.

### Final Answer:
The peripheral proteins found in the fluid mosaic model of the membrane are **superficially attached**.

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