Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits.

Question

Which of the following is an exception to the above statement?

a. a steroid

b. cellulose

c. DNA

d. an enzyme

e. a contractile protein

I'm thinking "steroid" since it's so much smaller and composed of fewer subunits compared to the other choices.

Answer 1

you're right, steroid is the correct answer. They come from a simple cholesterol precursor

Answer 2

Cellulose is made of glucose monomers

DNA is a polymer, it has a phosphate sugar backbone, and just think of the enzyme "DNA polymerase". That should be proof enough for that option

An enzyme is a protein (or numerous proteins); it is made of amino acids.

option E is also a protein

A is the correct answer.