Biochemistry Part 2

Which of the following functional groups can be found in the side chains of polar amino acids with uncharged side chains?

• Phenol, hydroxyl, thiol, and amide

• Alkyl, methyl, and ethyl

• Carboxyl, phosphate, and sulfide

• Ether, alkene, and alkyne

At physiologic pH, what is the net charge of the side chains of polar amino acids with uncharged side chains?

• Positive

• Negative

• No net charge

• Both positive and negative

Why do polar amino acids with uncharged side chains tend to cluster on the exterior of proteins?

• They are hydrophobic

• They are hydrophilic

• They are nonpolar

• They are aromatic

Which amino acid is shown in the diagram with a phenol group in its side chain?

• Serine

• Tyrosine

• Alanine

• Glycine

Which functional group is present in the side chain of Serine?

• Carboxyl

• Hydroxyl

• Amide

• Sulfhydryl

Which of the following amino acids contains a sulfur atom in its side chain?

• Threonine

• Cysteine

• Asparagine

• Glutamine

Which amino acid has an amide group in its side chain and a two-carbon chain between the alpha carbon and the amide group?

• Threonine

• Cysteine

• Asparagine

• Glutamine

Identify the amino acid that has a hydroxyl group (-OH) attached to its side chain.

• Threonine

• Cysteine

• Asparagine

• Glutamine

Compare the structures of Asparagine and Glutamine. What is the main structural difference between their side chains?

• Asparagine has a longer carbon chain in its side chain than Glutamine.

• Glutamine has a longer carbon chain in its side chain than Asparagine.

• Both have the same length of carbon chain in their side chains.

• Asparagine contains a sulfur atom, while Glutamine does not.

If a mutation replaced a threonine residue with a cysteine residue in a protein, which new chemical property would be introduced at that position?

• Introduction of an amide group

• Introduction of a sulfur-containing group

• Introduction of a second carboxyl group

• Introduction of a longer carbon chain