Plasma membrane is made of

Options

A. Protein
B. Lipids
C. Carbohydrates
D. Both A and B

Answer

**Step-by-Step Solution:**

1. **Understanding the Plasma Membrane**: The plasma membrane, also known as the cell membrane, is a vital structure found in all cells. It serves as a barrier that separates the interior of the cell from the external environment.

2. **Composition of the Plasma Membrane**: The plasma membrane is primarily composed of two main types of molecules: lipids and proteins.

3. **Lipids**: The most significant type of lipid found in the plasma membrane is phospholipids. These molecules have a hydrophilic (water-attracting) "head" and two hydrophobic (water-repelling) "tails." They arrange themselves in a bilayer, with the hydrophilic heads facing outward towards the water inside and outside the cell, and the hydrophobic tails facing inward, away from the water.

4. **Proteins**: The plasma membrane also contains various proteins that are embedded within or attached to the lipid bilayer. These proteins play crucial roles in transport, signaling, and maintaining the structure of the membrane.

5. **Carbohydrates**: While carbohydrates are present in the plasma membrane, they are not a major component. Instead, they are usually found attached to proteins (forming glycoproteins) or lipids (forming glycolipids) and are involved in cell recognition and signaling.

6. **Conclusion**: Based on the composition of the plasma membrane, we can conclude that it is primarily made up of proteins and lipids. Therefore, the correct answer to the question is "both A and B."

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