MCB: All Exam Questions and Answers 2023 with
complete solution;(MCB test bank)
50 multiple choice questions, covering all the topics we've taught you over the course of
the semester. The exam will be split into 4 sections: 1) Proteins (10 points) 2) DNA (10
points), 3) Transcription & Translation (10 points) , and 4) Energy & Metabolism (20
points). The best way to prepare for this exam is to review your old exams and focus on
the "big pictures" of each lecture using the "specifics to know" provided. You can expect
1 or 2 questions per lecture
...
Exam 1 version A
protein structure and function
Many types of non-covalent interactions are electrostatic in nature; one notable
exception is
A) Hydrogen bond
C) Ionic interaction
B) Van der Waals interaction
D) Hydrophobic interaction
D
2. Maintaining correct pH is very important for living systems. Which of the following
molecules is
important for pH control in living systems?
A) Proteins, especially those with high content of histidine residues
B) Dihydrogen phosphate and hydrogen phosphate
C) Bicarbonate
D) All of the above
D
3. While many biochemists use the terms "aspartate" and "aspartic acid"
interchangeably, they do refer to
different things. Which of the following regarding these two terms is true?
A) Aspartate is the conjugate base of aspartic acid.
B) Aspartate is converted to aspartic acid upon an increase in pH.
C) Aspartic acid is converted to aspartate upon a decrease in pH.
D) All of the above.
A
4. Most likely, the diagram on the right illustrates
A) A hydrogen bond formed between a base-pair
B) A hydrogen bond formed between two adjacent beta-strands
C) An ionic interaction between two adjacent alpha helices
D) A hydrogen bond formed between two adjacent alpha helices
picture
B
5. Change in pH can alter the charge status of protein molecules in aqueous solution.
For example, as pH
,decreases, protein molecules in aqueous solution tend to become
A) More protonated and more positively charged
B) Less protonated and more negatively charged
C) More stable and active
D) None of the above
A
6. Val, Leu, Ile, and Thr are considered as essential amino acids for humans, meaning
we have to get
them from our diet. Structurally, what is a common feature shared by those four
essential amino acids?
A) They all have a polar side chain
B) They all have a non-polar side chain
C) They all have a branched side chain
D) They all have an acidic side chain
C
7. The chemical structure shown on the right is the side chain of _______________,
which can function as a _________________ in the active site of an enzyme.
A) Proline; hydrogen bond acceptor
B) Histidine; proton acceptor
C) Tyrosine; hydrogen bond acceptor
D) Histidine; proton donor
picture
B
8. Cystine is formed via
A) Reduction of disulfide bond
B) Oxidation of the side chain of two cysteines
C) Dimerization between a cysteine and a tyrosine
D) Dimerization between a cysteine and a methionine
B
9. Which of the following statements is true regarding the two
amino acids shown on the right?
A) Both can be synthesized using pyruvate as a direct precursor
B) Both can be synthesized using oxaloacetate as a direct precursor
C) The one on the left but not the one on the right can be
synthesized using pyruvate as a direct precursor
D) Both are D-aspartate
picture
B
10. Histidine is an amino acid with three titratable groups: an −NH3+ group (pKa=9.2), a
−COOH group (pKa=1.8) and an imidazole (amine-like) group (pKa=6.0). The pI of
histidine is
A) 5.5
B) 7.6
C) 3.9
D) 8.5
,B
11. As an inhibitor for the shikimate pathway, glyphosate (roundup) is able to kill weeds
because
A) It blocks the synthesis of branched chain amino acids such as Ile and Val
B) It blocks the conversion of alpha-ketoglutarate to glutamate
C) It blocks the synthesis of aromatic amino acids such as Phe and Trp
D) It stimulates human beings to pull the weeds out of their yard
C
12. Which of the following sets of amino acids have three ionizable groups?
A) Ala, Pro, Asn
B) Asn, Asp, Gln
C) Asp, Ser, Trp
D) Asp, Cys, Tyr
D
picture of petptide chain with side chains: CH3, CH2(ring)OH, CH2COO-, H
13. The sequence of this peptide is
A) AFDG B) AYDG C) AYEG D) GYEA
14. The isoelectric point (pI) of the peptide is:
A) 3.6 B) 6.1 C) 6.5 D) 7.0
sequence:
pI:
13) B
14)a
15. Which of the following residues are rarely found in an alpha helix?
A) Glu, Arg, Lys
B) Tyr, Phe, Leu
C) Ser, Val, Thr
D) Phe, Trp, Tyr
C
16. The sequence of the dipeptide shown on the right is _____________, and the bond
# _______ has a partial double bond feature and thus cannot freely rotate.
A) FL, #3
B) HK, #4
C) HR, #3
C) RH, #3
picture
C
17. Which of the following statements is true regarding the following
peptide?
A) This is a tetrapeptide, and it can absorb light at 280 nm
B) This is a tripeptide, and it cannot absorb light at 280 nm
, C) This is a pentapeptide, and it can absorb light at 280 nm
D) This is a pentapeptide, and it carries two net positive charges at pH 1
picture
C
18. The tertiary structure of ribonuclease is stabilized by four pairs of disulfide bonds. In
the Anfinsen
experiment, two chemical reagents - urea and beta-mercaptoethanol - were used. The
function of urea
is to _________ and the function of beta-mercaptoethanol is to ______________.
Between these two
reagents, this one _____________ should be removed first to ensure correct refolding
of the protein.
A) denature the protein; oxidize the protein; beta-mercaptoethanol
B) denature the protein; reduce the disulfide bonds; urea
C) reduce the disulfide bonds; denature the protein; beta-mercaptoethanol
D) solubilize the protein; reduce the disulfide bonds; urea
B
19. Which of the following correctly describes the order of events in determining protein
structure using
X-ray crystallography?
A) Growing crystal; purifying protein; diffracting crystal using X-ray; solving the structure
B) Purifying protein; growing crystal; diffracting crystal using X-ray; solving the structure
C) Purifying protein; solving the structure; growing crystal; diffracting crystal using X-ray
D) Growing crystal; diffracting crystal using X-ray; purifying protein; solving the structure
B
20. In general, an anti-parallel beta sheet is slightly more stable than a parallel beta
sheet. This is because
A) An anti-parallel beta sheet always contains a higher content of hydrophobic residues
B) An anti-parallel beta sheet always has more strands
C) An anti-parallel beta sheet allows the formation of stronger hydrogen bonds
D) All of the above
C
21. A mixture of four proteins - G protein (92 kDa), GPCR (50 kDa), MAPK (35 kDa),
and p53 (53 kDa)
- is applied to a gel-filtration column; the protein that comes out of the column first (the
earliest) is
A) G protein
B) GPCR
C) MAPK
D) p53
A
22. A mixture of four proteins - Histone H1 (pI 10.7), p53 (pI 6.83), Ras (pI 6.33), and
trypsinogen (pI 9.3) - is applied to a cation-exchange column (i.e., the matrix is
composed of beads that contain negative charges) at pH 7. Which of the proteins will
come out of the column last (the latest)?
A) Histone H1
complete solution;(MCB test bank)
50 multiple choice questions, covering all the topics we've taught you over the course of
the semester. The exam will be split into 4 sections: 1) Proteins (10 points) 2) DNA (10
points), 3) Transcription & Translation (10 points) , and 4) Energy & Metabolism (20
points). The best way to prepare for this exam is to review your old exams and focus on
the "big pictures" of each lecture using the "specifics to know" provided. You can expect
1 or 2 questions per lecture
...
Exam 1 version A
protein structure and function
Many types of non-covalent interactions are electrostatic in nature; one notable
exception is
A) Hydrogen bond
C) Ionic interaction
B) Van der Waals interaction
D) Hydrophobic interaction
D
2. Maintaining correct pH is very important for living systems. Which of the following
molecules is
important for pH control in living systems?
A) Proteins, especially those with high content of histidine residues
B) Dihydrogen phosphate and hydrogen phosphate
C) Bicarbonate
D) All of the above
D
3. While many biochemists use the terms "aspartate" and "aspartic acid"
interchangeably, they do refer to
different things. Which of the following regarding these two terms is true?
A) Aspartate is the conjugate base of aspartic acid.
B) Aspartate is converted to aspartic acid upon an increase in pH.
C) Aspartic acid is converted to aspartate upon a decrease in pH.
D) All of the above.
A
4. Most likely, the diagram on the right illustrates
A) A hydrogen bond formed between a base-pair
B) A hydrogen bond formed between two adjacent beta-strands
C) An ionic interaction between two adjacent alpha helices
D) A hydrogen bond formed between two adjacent alpha helices
picture
B
5. Change in pH can alter the charge status of protein molecules in aqueous solution.
For example, as pH
,decreases, protein molecules in aqueous solution tend to become
A) More protonated and more positively charged
B) Less protonated and more negatively charged
C) More stable and active
D) None of the above
A
6. Val, Leu, Ile, and Thr are considered as essential amino acids for humans, meaning
we have to get
them from our diet. Structurally, what is a common feature shared by those four
essential amino acids?
A) They all have a polar side chain
B) They all have a non-polar side chain
C) They all have a branched side chain
D) They all have an acidic side chain
C
7. The chemical structure shown on the right is the side chain of _______________,
which can function as a _________________ in the active site of an enzyme.
A) Proline; hydrogen bond acceptor
B) Histidine; proton acceptor
C) Tyrosine; hydrogen bond acceptor
D) Histidine; proton donor
picture
B
8. Cystine is formed via
A) Reduction of disulfide bond
B) Oxidation of the side chain of two cysteines
C) Dimerization between a cysteine and a tyrosine
D) Dimerization between a cysteine and a methionine
B
9. Which of the following statements is true regarding the two
amino acids shown on the right?
A) Both can be synthesized using pyruvate as a direct precursor
B) Both can be synthesized using oxaloacetate as a direct precursor
C) The one on the left but not the one on the right can be
synthesized using pyruvate as a direct precursor
D) Both are D-aspartate
picture
B
10. Histidine is an amino acid with three titratable groups: an −NH3+ group (pKa=9.2), a
−COOH group (pKa=1.8) and an imidazole (amine-like) group (pKa=6.0). The pI of
histidine is
A) 5.5
B) 7.6
C) 3.9
D) 8.5
,B
11. As an inhibitor for the shikimate pathway, glyphosate (roundup) is able to kill weeds
because
A) It blocks the synthesis of branched chain amino acids such as Ile and Val
B) It blocks the conversion of alpha-ketoglutarate to glutamate
C) It blocks the synthesis of aromatic amino acids such as Phe and Trp
D) It stimulates human beings to pull the weeds out of their yard
C
12. Which of the following sets of amino acids have three ionizable groups?
A) Ala, Pro, Asn
B) Asn, Asp, Gln
C) Asp, Ser, Trp
D) Asp, Cys, Tyr
D
picture of petptide chain with side chains: CH3, CH2(ring)OH, CH2COO-, H
13. The sequence of this peptide is
A) AFDG B) AYDG C) AYEG D) GYEA
14. The isoelectric point (pI) of the peptide is:
A) 3.6 B) 6.1 C) 6.5 D) 7.0
sequence:
pI:
13) B
14)a
15. Which of the following residues are rarely found in an alpha helix?
A) Glu, Arg, Lys
B) Tyr, Phe, Leu
C) Ser, Val, Thr
D) Phe, Trp, Tyr
C
16. The sequence of the dipeptide shown on the right is _____________, and the bond
# _______ has a partial double bond feature and thus cannot freely rotate.
A) FL, #3
B) HK, #4
C) HR, #3
C) RH, #3
picture
C
17. Which of the following statements is true regarding the following
peptide?
A) This is a tetrapeptide, and it can absorb light at 280 nm
B) This is a tripeptide, and it cannot absorb light at 280 nm
, C) This is a pentapeptide, and it can absorb light at 280 nm
D) This is a pentapeptide, and it carries two net positive charges at pH 1
picture
C
18. The tertiary structure of ribonuclease is stabilized by four pairs of disulfide bonds. In
the Anfinsen
experiment, two chemical reagents - urea and beta-mercaptoethanol - were used. The
function of urea
is to _________ and the function of beta-mercaptoethanol is to ______________.
Between these two
reagents, this one _____________ should be removed first to ensure correct refolding
of the protein.
A) denature the protein; oxidize the protein; beta-mercaptoethanol
B) denature the protein; reduce the disulfide bonds; urea
C) reduce the disulfide bonds; denature the protein; beta-mercaptoethanol
D) solubilize the protein; reduce the disulfide bonds; urea
B
19. Which of the following correctly describes the order of events in determining protein
structure using
X-ray crystallography?
A) Growing crystal; purifying protein; diffracting crystal using X-ray; solving the structure
B) Purifying protein; growing crystal; diffracting crystal using X-ray; solving the structure
C) Purifying protein; solving the structure; growing crystal; diffracting crystal using X-ray
D) Growing crystal; diffracting crystal using X-ray; purifying protein; solving the structure
B
20. In general, an anti-parallel beta sheet is slightly more stable than a parallel beta
sheet. This is because
A) An anti-parallel beta sheet always contains a higher content of hydrophobic residues
B) An anti-parallel beta sheet always has more strands
C) An anti-parallel beta sheet allows the formation of stronger hydrogen bonds
D) All of the above
C
21. A mixture of four proteins - G protein (92 kDa), GPCR (50 kDa), MAPK (35 kDa),
and p53 (53 kDa)
- is applied to a gel-filtration column; the protein that comes out of the column first (the
earliest) is
A) G protein
B) GPCR
C) MAPK
D) p53
A
22. A mixture of four proteins - Histone H1 (pI 10.7), p53 (pI 6.83), Ras (pI 6.33), and
trypsinogen (pI 9.3) - is applied to a cation-exchange column (i.e., the matrix is
composed of beads that contain negative charges) at pH 7. Which of the proteins will
come out of the column last (the latest)?
A) Histone H1
