Question

Membrane phospholipids

a. have hydrophobic heads that face the center of the membrane and are shielded from water.
b. have hydrophilic tails that face outward and are exposed to water.
c. are able to drift about in the plasma membrane.
d. remain fluid because they are tightly packed against one another.

Answer 1

Membrane phospholipids are amphiphilic, with hydrophilic heads facing the aqueous environment and hydrophobic tails shielded from water, forming a flexible lipid bilayer. The correct statement about their behavior is that they are able to drift within the plasma membrane.

Step-by-step explanation:

Membrane phospholipids are crucial components in the structure of the plasma membrane. These molecules are amphiphilic, meaning they have both hydrophilic (water-loving) and hydrophobic (water-fearing) parts. The hydrophilic heads of these molecules face the aqueous environment on either side of the membrane due to their affinity for water. In contrast, the hydrophobic tails face towards each other, away from water, thus avoiding the aqueous surroundings. This arrangement results in a lipid bilayer that forms the fundamental barrier of the cell membrane, keeping the internal components of the cell separate from the external environment.

Given the options provided by the student, the correct statement is that membrane phospholipids c. are able to drift about in the plasma membrane. This characteristic allows membrane phospholipids to form a flexible barrier that can adapt to various cellular processes including the movement of substances across the membrane and the fusion of vesicles.

Answer 2

Option-C

Step-by-step explanation:

The phospholipids are the major constituents of the cell membrane of a cell. The phospholipids contains the glycerol attached to the phosphate group and forms the hydrophilic heads whereas the fatty acid tails from the hydrophobic portion of the membrane.

The hydrophobic head face outwards whereas the tails face inwards. The structure of the membrane as arranged in bi lipid layer form and in such a way that the membrane molecules can move. The other molecules present in the membrane like the proteins can drift in the membrane.

Thus, Option-C is correct.