Question

The plasma membrane is made up of

• A. Protein
• B. Lipid
• C. Carbohydrate
• D. Both A and B

Answer 1

The correct option is D

Both A and B

The correct option is D.

Explanation of the correct option:

1. The plasma membrane is the outermost covering of the cell that is mainly composed of phospholipids and proteins.
2. The fluid mosaic model explains the role of proteins and lipids in the plasma membrane.
3. A phospholipid bilayer comprises hydrophilic heads and hydrophobic tails that allow only selected particles to pass through.
4. The proteins act as channels to carry the substances in and out of the membrane.

Explanation of the incorrect options:

Option A:

1. Protein is present in the plasma membrane in three forms that are integral, peripheral, and glycoprotein.
2. It is the second major component of a plasma membrane.

Option B:

1. Phospholipids are arranged in a bilayer which makes the basic fabric of the plasma membrane.
2. It is amphipathic that has both hydrophobic and hydrophilic regions.

Option C:

1. Carbohydrates are the third major component of the plasma membrane
2. It is present on the outer surface of the membrane and attached either to phospholipids or to proteins.

Final answer: Plasma membrane is made up of proteins and lipids.