Question

According to fluid mosaic model, plasma membrane is composed of

• A. phospholipids and oligosaccharides
• B. phospholipids and hemicellulose
• C. phospholipids and integral proteins
• D. phospholipids, extrinsic proteins and intrinsic proteins.

Answer 1

Answer: (D)

Plasma membrane consists of lipids (20-79%), proteins (20-70%), carbohydrates (1-5%) and water (20%). Lipid molecules possess both hydrophobic and hydrophilic ends and are thus arranged in the form of lipid bilayer. Most common lipid of the bilayer is phospholipid. Protein molecules occur at places both inside (intrinsic proteins) and on the outer side (extrinsic proteins) of the phospholipid bilayer.