Quiz on Proteins and Amino Acids

Proteins are polymers in which

• branched chains of amino acids are present.

• unbranched chains of amino acids are present.

• both unbranched and branched chains of amino acids are present.

• alternating amino acid and glucose monomer units are present.

Which of the following is not a property of protein at isoelectric pH (pI)?

• Protein possess equal number of positive and negative charges.

• Below the isoelectric point, they possess net positive charge.

• Proteins will have maximum solubility at pI.

• Proteins exist in zwitter ionic form.

Amino acids with acidic side chain contain an extra carboxylic group, because of this

• they tend to become polar and ionizable

• they are not capable of undergoing ionization

• they tend to become non-polar and ionizable

• they attain stability and obtain a net charge of zero.

Which of the following is the only cyclic amino acid, also known as imino acid?

• Alanine

• Phenylalanine

• Tyrosine

• Proline

Which of the following amino acids would be classified as a polar neutral amino acid?

Which pair of ketogenic amino acids breaks down to form ketone bodies?

• Phenylalanine and isoleucine

• Cysteine and methionine

• Tryptophan and tyrosine

• Leucine and lysine

Which of the following amino acids is non-essential?

• Arginine

• Serine

• Methionine

• Tryptophan

Which of the following sets of elements is a possible composition for a standard amino acid?

• C, H, and N

• C, H, O, and S

• C, H, N, and S

• C, H, O, N, and S

Which R-group interactions between the following pairs of amino acids would produce a disulfide bond?

• cysteine-cysteine

• proline-proline

• alanine-glycine

• methionine-glycine

Which of these functions of amino acids is crucial in the production of energy?

• Amino acids are imperative for sustaining the health of the human body.

• The carbon skeletons of amino acids are used as a fuel source in the citric acid cycle.

• The amino acids are used by various tissues to synthesize proteins and to produce nitrogen-containing compounds.

• The linear sequence of amino acid residues in a polypeptide chain determines the three-dimensional configuration of a protein.