Question

molecule\tstructure\tfunction
carbohydrates\tpolymers of glucose rings\t
proteins\tpolymers of amino acids\t
lipids\tglycerol + fatty acids\t
a student is comparing the different macromolecule types for a biology class. the student described the structure of the molecules but then must complete the table for the functions of these molecules. which description accurately compares the functions of carbohydrates and proteins and can be used to complete the table?
a\tcarbohydrates and proteins can both be used for energy by the cell.
b\tcarbohydrates and proteins can both be used as enzymes by the cell.
c\tcarbohydrates and proteins can both be used for signaling by the cell.
d\tcarbohydrates and proteins share no common functions since their structures are different.

Explanation:

Carbohydrates are primary energy sources (e.g., glucose). Proteins can be used for energy when other sources are depleted. Enzymes are proteins, not carbohydrates. Signaling molecules include some proteins but not typical carbohydrates. They do share the energy function, so option A is correct.

Answer:

A. Carbohydrates and proteins can both be used for energy by the cell.