Question

1. when proteins are formed the _ of one amino acid combines with the __ of a second amino acid for form a:

a. side chain r - group; carboxyl group; monopeptide
b. side chain r - group; amino group; polypeptide
c. amino group; carboxyl group; monopeptide
d. amino group; carboxyl group; polypeptide

1. there are 20 standard amino acids. how do they differ from each other?

a. the amino groups can vary
b. the carboxyl groups can vary
c. the carbons can vary
d. the side chains can vary

1. which of the following statements best describes the impact of the structure of proteins?

a. shape is driven by chemistry; shape dictates function
b. shape is driven by chemistry; polarity dictates function
c. shape is driven by environment; environment dictates function
d. shape is driven by chemistry; environment dictates function
14 for which level of structure in proteins do the side chains play the biggest role?
a. secondary
b. tertiary
c. primary
d. quaternary

1. how does a protein change during denaturation and why is this important?

a. the protein loses amino acids; the polarity may be changed
b. the protein loses its shape; the protein cannot function
c. the protein loses hoh; dehydration synthesis cannot occur
d. the protein gains amino acids; the protein changes into a different protein

1. proteins play many critical roles in organisms. which of the following pairs correctly connects the function of a protein to its class?

a. cytoskeleton is structural; antibodies are defense
b. speed regulation is enzymes; muscles are hormonal

Explanation:

• Question 11: Amino acids combine via a peptide bond where the amino group of one reacts with the carboxyl group of another. A polypeptide is formed by multiple amino acids.
• Question 12: The 20 standard amino acids differ in their side - chain R - groups.
• Question 13: Protein shape (driven by chemistry) dictates its function.
• Question 14: Side chains play the biggest role in tertiary structure (3D folding influenced by side - chain interactions).
• Question 15: Denaturation causes a protein to lose its shape, and a mis - shaped protein cannot function.
• Question 16: The cytoskeleton is a structural protein, and antibodies are defense proteins.

Answer:

1. d. amino group; carboxyl group; polypeptide
2. d. the side chains can vary
3. a. shape is driven by chemistry; shape dictates function
4. b. tertiary
5. b. the protein loses its shape; the protein cannot function
6. a. cytoskeleton is structural; antibodies are defense