Question

Assume that a single layer of phospholipids coat the water in a beaker. which part of the phospholipid molecule will face the air?

a.the phosphate groups
b.the hydrocarbon tails
c.the phospholipids would dissolve and not form a membrane coat
d.both heads and tails as the molecules are amphipathic and will lie sideways

Answer 1

The part of the phospholipid molecule that will face the water, as it is labelled to be hydrophilic would be the polar phosphate group. The correct response would be A.

Answer 2

Answer: The correct answer is-

b.the hydrocarbon tails.

A phospholipid molecule comprises of a head group (that contains polar phosphate molecule) that is hydrophilic ( water attracting groups due to formation of hydrogen bonding or ionic bonds with water molecules) and two tails of fatty acid ( which are hydrophobic that is water repelling groups).

In this question, a single layer of phospholipid coats the water in a beaker. This means that head group of this layer is in contact of water ( present in the beaker) and the two fatty acid tails of hydrocarbon ( that are water repelling) are facing air.

Thus, option b) is the right answer.