How can a cell make many different kinds of proteins out of only 20 amino acids? Of the myriad possibilities, how does the cell 'know' which proteins to make?

The primary building blocks (monomers) of proteins are: 

a) Glucose molecules.

b) Lipids.

c) Nucleotides.

d) Amino acids.

e) None of these.

Which two functional groups are always found in amino acids?

a) Carbonyl and amino groups.

b) Carboxyl and amino groups.

c) Amino and sulfhydryl groups.

d) Hydroxyl and carboxyl groups.

What term is used for an amino acid chain that has greater than 50 covalently linked amino acids?

a) Protein.

b) Peptide.

c) Amino acid.

d) Polypeptide.

The specific amino acid sequence in a protein is its:

a) Primary structure.

b) Secondary structure.

c) Tertiary structure.

d) Quaternary structure.