Amino Acids

Question 1

What is the general structural formula for all standard amino acids?

Accepted Answer

H2N-C(R)-COOH

Answer

H3O-C(R)-NH2

Answer

R-C(NH2)-OH

Answer

HOOC-C(H)-NHOH

Question 2

What type of bond links amino acids together to form a polypeptide chain?

Accepted Answer

Peptide bond

Answer

Glycosidic bond

Answer

Ester bond

Answer

Hydrogen bond

Question 3

Which of the following is an example of an amino acid with a nonpolar side chain?

Accepted Answer

Alanine

Answer

Lysine

Answer

Serine

Answer

Aspartic acid

Question 4

At what pH would you expect an amino acid with a negatively charged side chain to be protonated?

Accepted Answer

Low pH

Answer

High pH

Answer

Neutral pH

Answer

It never gets protonated

Question 5

Which level of protein structure is primarily stabilized by hydrogen bonds between amino and carboxyl groups of amino acids in the polypeptide backbone?

Accepted Answer

Secondary structure

Answer

Primary structure

Answer

Tertiary structure

Answer

Quaternary structure

Question 6

What is the name given to amino acids that cannot be synthesized by the human body and must be obtained from the diet?

Accepted Answer

Essential amino acids

Answer

Nonessential amino acids

Answer

Conditional amino acids

Answer

Magical amino acids

Question 7

Which of the following is an aromatic amino acid?

Accepted Answer

Tryptophan

Answer

Glycine

Answer

Valine

Answer

Proline

Question 8

What is the isoelectric point (pI) of an amino acid?

Accepted Answer

The pH at which the amino acid has no net charge

Answer

The pH at which the amino acid is fully protonated

Answer

The pH at which the amino acid is fully deprotonated

Answer

The pH at which the amino acid changes color

Question 9

What is the role of chaperone proteins in protein folding?

Accepted Answer

To assist in the proper folding of other proteins

Answer

To break down misfolded proteins

Answer

To transport proteins across cell membranes

Answer

To add sugar molecules to proteins

Question 10

A mutation in a gene causes a glutamic acid residue to be replaced by an alanine residue. How will the protein structure change?

Accepted Answer

The protein's structure and function may be altered due to the change in polarity.

Answer

The protein will remain exactly the same because the amino acids are similar.

Answer

The protein will immediately degrade because alanine is toxic.

Answer

The protein will become fluorescent.