18. Amino Acids and Proteins

Consider the amino acids lysine, valine, and aspartate in an enzyme. State which of these amino acids have R groups that would:

c. form hydrogen bonds

Consider the amino acids lysine, valine, and aspartate in an enzyme. State which of these amino acids have R groups that would:

d. form salt bridges

Classify each of the following proteins according to its function:

a. hemoglobin, oxygen carrier in the blood

Classify each of the following proteins according to its function:

c. keratin, a protein found in hair

Classify each of the following proteins according to its function:

a. insulin, a protein needed for glucose utilization

Classify each of the following proteins according to its function:

c. casein, milk protein

List the type of attractive force disrupted and the level of protein structure changed by the following denaturing treatments:

a. adding salt to soy milk to make tofu

Identify each of the following statements as characteristic of protein denaturation or protein hydrolysis. 

a. Milk curdles when lemon juice is added to it.

Identify each of the following statements as characteristic of protein denaturation or protein hydrolysis. 

b. A protein breaks up into amino acid fragments.

Identify the level of protein structure associated with each of the following:

d. salt bridges between polypeptides

Indicate what type(s) of intermolecular forces are disrupted and what level of protein structure is changed by the following denaturing treatments:

a. an egg placed in water at 100 °C and boiled for 10 minutes

Indicate what type(s) of intermolecular forces are disrupted and what level of protein structure is changed by the following denaturing treatments:

c. egg whites whipped in a mixing bowl to make meringue

Describe the changes that occur in the primary structure when a protein is denatured versus when a protein is hydrolyzed.

Identify the level of protein structure associated with each of the following:

d. intermolecular forces between R groups

Identify the level of protein structure associated with each of the following:

b. disulfide bridge