Question

Phospholipids are arranged to form the plasma membrane so that

A. The heads are facing the extra cellular fluid and tails are internal

B. The heads of the outer layer phospholipids face the tails of the inner layer

C. The tails of the outer layer phospholipids face the heads of the inner layer

D. The heads of the internal and the tails are facing the extra cellular and intracellular fluid

Answer 1

Ans.

Plasma membrane is an outer covering of cells, made up of lipid bilayer and protein molecules.

The lipids present in plasma membrane show amphipathic nature as their head groups are hydrophilic, while inner tail groups are hydrophobic in nature.

The hydrophilic heads face the extracellular fluid and intracellular fluid, while the hydrophobic tails point inward, to provide a double layer structure.

A bilayer arrangement of lipid molecules is shown in attached figure.

Thus, the correct answer is option). A.