2025 BIOC201W1 Introduction to Biomolecules
06 June 2025
SI Leader: STHEMBISO MSANE,
MCQ
1. The single letter symbol denotes glutamine is
A. L
B. G
C. T
D. Q
E. None of the above
2. Proline is unique among the amino acids because
A. It is the only amino acid whose alpha carbon is not chiral
B. It exists naturally in two isomeric forms
C. Its alpha amino group is a primary amine
D. Its alpha amino group is a secondary amine
E. Its alpha amino group is a tertiary amine
3. Which of the following groups of amino acids only contains non-polar and neutral
amino acids?
A. Ile, Lys, and Gly
B. Phe, Tyr, and His
C. Gln, Ser, and Val
D. Ala, Phe, and Val
E. None of the above
4. Which of the following groups of amino acids contains only polar and charged amino
acids?
A. Phe, Tyr, and His
B. Glu, His, and Arg
C. Asn, Ser, and Val
D. Ala, Phe, and Val
E. None of the above
5. The ά amino acids have a carboxyl group group with a pKa around …., and an amino
group with a pKa near ….
A. 1.1, and 12.1
, B. 2.0, and 9.5
C. 3.3, and 10.5
D. 6.5, and 8.0
E. 9.0, and 2.5
6. Assume that pKa1 =2.18; pKa= 8.95 and pKa=10.53 for Lysine. What is the
isoelectric point of this AA?
A. 5.29
B. 6.34
C. 7.22
D. 10.26
E. None of the above
7. When methionine is added to a buffered solution with pH of 7.0, Met becomes;
A. A cation
B. A zwitterion
C. Non-polar
D. A dipolar ion
E. Both B and D
8. A modified amino group acid in a protein that is employed to regulate the activity of
an enzyme is
A. 5-methyllysine
B. 4-hydroxyproline
C. Desmosine
D. O-phosphoserine
E. Homocysteine
9. Which group of amino acids absorbs UV light most significantly at 280 nm?
A. Thr, His, and Phe
B. Cys, Asp, and Trp
C. Phe, Pro, and His
D. His, Phe and Tyr
E. Trp, Tyr and Phe
10. The following reactions is employed to quantitatively determine amino acids
concentration.
A. Ninhydrin reaction
B. Biuret reaction
06 June 2025
SI Leader: STHEMBISO MSANE,
MCQ
1. The single letter symbol denotes glutamine is
A. L
B. G
C. T
D. Q
E. None of the above
2. Proline is unique among the amino acids because
A. It is the only amino acid whose alpha carbon is not chiral
B. It exists naturally in two isomeric forms
C. Its alpha amino group is a primary amine
D. Its alpha amino group is a secondary amine
E. Its alpha amino group is a tertiary amine
3. Which of the following groups of amino acids only contains non-polar and neutral
amino acids?
A. Ile, Lys, and Gly
B. Phe, Tyr, and His
C. Gln, Ser, and Val
D. Ala, Phe, and Val
E. None of the above
4. Which of the following groups of amino acids contains only polar and charged amino
acids?
A. Phe, Tyr, and His
B. Glu, His, and Arg
C. Asn, Ser, and Val
D. Ala, Phe, and Val
E. None of the above
5. The ά amino acids have a carboxyl group group with a pKa around …., and an amino
group with a pKa near ….
A. 1.1, and 12.1
, B. 2.0, and 9.5
C. 3.3, and 10.5
D. 6.5, and 8.0
E. 9.0, and 2.5
6. Assume that pKa1 =2.18; pKa= 8.95 and pKa=10.53 for Lysine. What is the
isoelectric point of this AA?
A. 5.29
B. 6.34
C. 7.22
D. 10.26
E. None of the above
7. When methionine is added to a buffered solution with pH of 7.0, Met becomes;
A. A cation
B. A zwitterion
C. Non-polar
D. A dipolar ion
E. Both B and D
8. A modified amino group acid in a protein that is employed to regulate the activity of
an enzyme is
A. 5-methyllysine
B. 4-hydroxyproline
C. Desmosine
D. O-phosphoserine
E. Homocysteine
9. Which group of amino acids absorbs UV light most significantly at 280 nm?
A. Thr, His, and Phe
B. Cys, Asp, and Trp
C. Phe, Pro, and His
D. His, Phe and Tyr
E. Trp, Tyr and Phe
10. The following reactions is employed to quantitatively determine amino acids
concentration.
A. Ninhydrin reaction
B. Biuret reaction
