21.The following amino acids are linked together: glycine–lysine–valine. This compound is which of the following peptides?

a.a dipeptide

b.a tripeptide

c.a polypeptide

d.an oligopeptide

22.Which of the following distinguishes hemoglobin from a polypeptide chain?

a.Hemoglobin is a tertiary structure.

b.Hemoglobin is denatured.

c.Hemoglobin is a complex of 4 polypeptide chains.

d.Hemoglobin contains a globin molecule within the heme structure.

23.Which of the following factors accounts for the weak electrical attractions within a protein’s polypeptide chains?

a.primary structure

b.secondary structure

c.tertiary structure

d.quaternary structure

24.Which of the following is an example of a protein with a quaternary polypeptide structure?

a.insulin

b.tryptophan

c.hemoglobin

d.two dipeptides bonded together

25.What is the process by which heat or acidity disrupts the normal shape of a protein chain?

a.digestion

b.condensation

c.denaturation

d.hydrogenation

26.The application of heat or acid to a protein that causes its shape to change is known as which of the following?

a.stiffening

b.condensation

c.denaturation

d.destabilization

27.What process results in the hardening of an egg when it is exposed to heat?

a.solidification

b.denaturation

c.condensation

d.protein interaction

28.After a hamburger is eaten, the hydrolysis of its proteins is initiated in which one of the following parts of the digestive system?

a.mouth

b.stomach

c.small intestine

d.large intestine

29.What is the name of the inactive form of the protein-splitting enzyme in the stomach?

a.peptidase

b.peptic acid

c.pepsinogen

d.propeptidase

30.Pepsin is active in which one of the following organs?

a.stomach

b.pancreas

c.small intestine

d.large intestine