Question

question: 13
the cell membrane is mainly made up of lipids and proteins, it acts as a barrier to the surrounding environment. which of the following statements about lipids best supports the argument that lipids help protect the contents of the cell?

a. lipids that are placed in water do not dissolve.

b. the tail of a lipid is made of carbon and hydrogen.

c. individual lipids in a membrane can rotate freely.

d. lipids are composed of a head and a thin tail.

Explanation:

The cell exists in an aqueous (water-based) environment, and its interior is also water-based. For lipids to act as a protective barrier, they must separate these water-based regions. Lipids are hydrophobic (water-fearing), so they do not dissolve in water. This property allows them to form a bilayer that blocks unregulated movement of water and water-soluble substances into/out of the cell, protecting the cell's contents. The other options describe structural or compositional details that do not directly explain the protective barrier function.

Answer:

A. Lipids that are placed in water do not dissolve.