Protein icebergs in a sea of lipids means

Options

A. units membrane model
B. fluid mosaic model
C. lamellar / sandwich model
D. micellar model

Answer

**Step-by-Step Solution:**

1. **Understanding the Phrase**: The phrase "protein icebergs in a sea of lipids" is a metaphor that describes the structure of the cell membrane. It suggests that proteins are embedded within a lipid bilayer, much like icebergs floating in water.

2. **Identifying the Model**: This description aligns with the Fluid Mosaic Model of the cell membrane proposed by Singer and Nicholson. This model illustrates that the cell membrane is not a static structure but rather a dynamic one where proteins can move laterally within the lipid bilayer.

3. **Components of the Cell Membrane**: The cell membrane is primarily composed of lipids (phospholipids) and proteins. The proteins can be categorized as:
- **Intrinsic (or Integral) Proteins**: These proteins are embedded within the lipid bilayer and can span across the membrane.
- **Extrinsic (or Peripheral) Proteins**: These proteins are located on the surface of the membrane and do not penetrate the lipid bilayer.

4. **Conclusion**: Given the description of "protein icebergs in a sea of lipids," it is clear that this refers to the Fluid Mosaic Model, which accurately depicts the arrangement and movement of proteins within the lipid bilayer of the cell membrane.

5. **Final Answer**: The correct answer is the Fluid Mosaic Model.

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