Quiz on Proteins and Amino Acids

Proteins are biochemical molecules consisting of:

• Monosaccharides

• Polypeptides

• Nucleotides

• Lipids

What type of bond joins amino acids in a polypeptide chain?

• Ester bond

• Glycosidic bond

• Peptide bond

• Hydrogen bond

Which of the following is a vital function of proteins?

• Energy storage

• Acting as biochemical catalysts (enzymes)

• Genetic information storage

• Insulation

Actin and myosin are examples of proteins with what kind of function?

• Enzymatic

• Structural or mechanical

• Signaling

• Immune response

Proteins are important for all of the following except:

• Cell signaling

• Immune responses

• Cell adhesion

• DNA replication

What is the isoelectric point of an amino acid?

• The pH at which it has a positive charge

• The pH at which it has a negative charge

• The pH at which it forms a zwitterion (net zero charge)

• The pH at which it denatures

Amino acids with neutral R groups have an isoelectric point near a pH of:

• 2

• 6

• 10

• 14

Amino acids with basic R groups have isoelectric points:

• Lower than 6

• Near 6

• Higher than 6

• That vary widely

Amino acids and proteins can act as buffers because they can react with:

• Only H3O+ ions

• Only OH- ions

• Both H3O+ and OH- ions

• Neither H3O+ nor OH- ions

Which amino acid contains a sulfhydryl group?

• Alanine

• Glycine

• Cysteine

• Serine