BIOCHEM ACS STUDY GUIDE | Actual Questions and Answers
Latest Updated 2026/2027 (Graded A+)
Each of the following subcellular structures contains DNA EXCEPT
• Question
A. the nucleus.
B. ribosomes.
C. chloroplasts.
D. mitochondria.
Correct Answer: B
• Question
In plant and animal cells, the three-dimensional integrity of the cell is maintained, in
part, by an internal network of filaments called
A. the cell wall.
B. the Golgi apparatus.
C. the cytoskeleton.
D. the endoplasmic reticulum.
Correct Answer: C
Of the following, which are prokaryotes?
• Question
A. viruses
B. bacteria
C. yeast
D. plant cells
Correct Answer: B
G° for the conversion of glycerol-3-phosphate to glycerol + Pi is -2.2 kcal/mole. Thus,
you can conclude that
• Question
A. this reaction will occur spontaneously.
B. this reaction may or may not occur spontaneously, depending on the
actual concentrations of reactants and products.
C. this reaction will only occur spontaneously if it is coupled to
another reaction that has a more favorable G°.
D. this reaction is so strongly favorable that it could be coupled to
drive an otherwise unfavorable cell reaction.
Correct Answer: B
,• Question
In most biochemical reactions, ∆PV is
A. negligible
B. positive
C. negative
D. dependent on ∆E
Correct Answer: A
According to the Second Law of Thermodymnamics,
• Question
A. the total entropy change in any reaction that occurs spontaneously must be greater
than 0.
B. the total entropy change in any reaction that occurs spontaneously must be less than
0.
C. the total entropy of the universe remains constant.
D. the total entropy of the universe is always decreasing.
Correct Answer: A
• Question
Which of the following is true?
A. Liquid and solid water have the same number of hydrogen bonds per molecule of
water
B. Liquid water has more hydrogen bonds per molecule than does solid water
C. Solid water has more hydrogen bonds per molecule than does liquid water
D. Hydrogen bonding is a major factor in the structure of gaseous water
E. None is true
Correct Answer: C
• Question
What is the pH of an aqueous solution that has a [OH-] of 3.45 x 10-5 M?
A. 3.47
B. 4.47
C. 5.53
D. 9.54
E. none of the above
Correct Answer: D
,• Question
A peptide was found to have a molecular mass of about 650 and upon hydrolysis
produced Ala, Cys, Lys, Phe, and Val in a 1:1:1:1:1 ratio. The peptide upon treatment
with Sanger's reagent produced DNP-Cys and exposure to carboxypeptidase produced
valine. Chymotrypsin treatment of the peptide produced a dipeptide that contained
sulfur and has a UV absorbance, and a tripeptide. Exposure of the peptide to trypsin
produced a dipeptide and a tripeptide. Deduce the sequence of the peptide.
A. Val-Ala-Lys-Phe-Cys
B. Cys-Lys-Phe-Ala-Val
C. Cys-Ala-Lys-Phe-Val
D. Cys-Phe-Lys-Ala-Val
E. Val-Phe-Lys-Ala-Cys
Correct Answer: D
• Question
Which amino acid has an R-group pKa closest to physiological pH?
A. lysine
B. histidine
C. glutamate
D. arginine
E. aspartate
Correct Answer: B
• Question
Which is true regarding the orientation of the R-groups in beta structures?
A. In the parallel beta sheet structures the amino acid R-groups are all on the same side
of the sheet.
B. In the antiparallel beta sheet structure the R-groups on alternate strands are on the
same side of the
sheet.
C. In parallel and antiparallel sheets consecutive R-groups on each peptide strand
alternate sides of the
sheet.
D. Because of the free rotation around the alpha carbon, the R-groups can seek the least
crowded
region and are not restricted to specific side of the sheet.
E. a and b
Correct Answer: C
, • Question
A reagent commonly employed to cleave disulfide bonds in proteins is
A. 2,4-dinitrofluorobenzene
B. urea
C. 2-mercaptoethanol
D. phenylisothiocyanate
E. cyanogen bromide
Correct Answer: C
• Question
With respect to a relaxed muscle, which of the following is true?
A. the number of actin-myosin cross-bridges is maximized and the muscle is shortened
B. the number of actin-myosin cross bridges is maximized and the muscle is stretched
C. the number of actin-myosin cross bridges is minimized and the muscle is shortened
D. the number of actin-myosin cross bridges is minimized and the muscle is stretched
E. none of the above
Correct Answer: D
• Question
Which of the following does not describe hemoglobin?
A. Hemoglobin is an oxygen transport protein.
B. Hemoglobin is an allosteric protein.
C. Hemoglobin has quaternary structure.
D. Copper ions are important in hemoglobin's ability to bind oxygen.
E. Hemoglobin is composed, in part, of an iron containing heme group.
Correct Answer: D
• Question
Which of the following would allow you to determine the isoelectric point of a protein?
A. protein quaternary structure
B. protein solubility as a function of pH
C. protein size
D. protein shape
E. protein tertiary structure
Correct Answer: B
Latest Updated 2026/2027 (Graded A+)
Each of the following subcellular structures contains DNA EXCEPT
• Question
A. the nucleus.
B. ribosomes.
C. chloroplasts.
D. mitochondria.
Correct Answer: B
• Question
In plant and animal cells, the three-dimensional integrity of the cell is maintained, in
part, by an internal network of filaments called
A. the cell wall.
B. the Golgi apparatus.
C. the cytoskeleton.
D. the endoplasmic reticulum.
Correct Answer: C
Of the following, which are prokaryotes?
• Question
A. viruses
B. bacteria
C. yeast
D. plant cells
Correct Answer: B
G° for the conversion of glycerol-3-phosphate to glycerol + Pi is -2.2 kcal/mole. Thus,
you can conclude that
• Question
A. this reaction will occur spontaneously.
B. this reaction may or may not occur spontaneously, depending on the
actual concentrations of reactants and products.
C. this reaction will only occur spontaneously if it is coupled to
another reaction that has a more favorable G°.
D. this reaction is so strongly favorable that it could be coupled to
drive an otherwise unfavorable cell reaction.
Correct Answer: B
,• Question
In most biochemical reactions, ∆PV is
A. negligible
B. positive
C. negative
D. dependent on ∆E
Correct Answer: A
According to the Second Law of Thermodymnamics,
• Question
A. the total entropy change in any reaction that occurs spontaneously must be greater
than 0.
B. the total entropy change in any reaction that occurs spontaneously must be less than
0.
C. the total entropy of the universe remains constant.
D. the total entropy of the universe is always decreasing.
Correct Answer: A
• Question
Which of the following is true?
A. Liquid and solid water have the same number of hydrogen bonds per molecule of
water
B. Liquid water has more hydrogen bonds per molecule than does solid water
C. Solid water has more hydrogen bonds per molecule than does liquid water
D. Hydrogen bonding is a major factor in the structure of gaseous water
E. None is true
Correct Answer: C
• Question
What is the pH of an aqueous solution that has a [OH-] of 3.45 x 10-5 M?
A. 3.47
B. 4.47
C. 5.53
D. 9.54
E. none of the above
Correct Answer: D
,• Question
A peptide was found to have a molecular mass of about 650 and upon hydrolysis
produced Ala, Cys, Lys, Phe, and Val in a 1:1:1:1:1 ratio. The peptide upon treatment
with Sanger's reagent produced DNP-Cys and exposure to carboxypeptidase produced
valine. Chymotrypsin treatment of the peptide produced a dipeptide that contained
sulfur and has a UV absorbance, and a tripeptide. Exposure of the peptide to trypsin
produced a dipeptide and a tripeptide. Deduce the sequence of the peptide.
A. Val-Ala-Lys-Phe-Cys
B. Cys-Lys-Phe-Ala-Val
C. Cys-Ala-Lys-Phe-Val
D. Cys-Phe-Lys-Ala-Val
E. Val-Phe-Lys-Ala-Cys
Correct Answer: D
• Question
Which amino acid has an R-group pKa closest to physiological pH?
A. lysine
B. histidine
C. glutamate
D. arginine
E. aspartate
Correct Answer: B
• Question
Which is true regarding the orientation of the R-groups in beta structures?
A. In the parallel beta sheet structures the amino acid R-groups are all on the same side
of the sheet.
B. In the antiparallel beta sheet structure the R-groups on alternate strands are on the
same side of the
sheet.
C. In parallel and antiparallel sheets consecutive R-groups on each peptide strand
alternate sides of the
sheet.
D. Because of the free rotation around the alpha carbon, the R-groups can seek the least
crowded
region and are not restricted to specific side of the sheet.
E. a and b
Correct Answer: C
, • Question
A reagent commonly employed to cleave disulfide bonds in proteins is
A. 2,4-dinitrofluorobenzene
B. urea
C. 2-mercaptoethanol
D. phenylisothiocyanate
E. cyanogen bromide
Correct Answer: C
• Question
With respect to a relaxed muscle, which of the following is true?
A. the number of actin-myosin cross-bridges is maximized and the muscle is shortened
B. the number of actin-myosin cross bridges is maximized and the muscle is stretched
C. the number of actin-myosin cross bridges is minimized and the muscle is shortened
D. the number of actin-myosin cross bridges is minimized and the muscle is stretched
E. none of the above
Correct Answer: D
• Question
Which of the following does not describe hemoglobin?
A. Hemoglobin is an oxygen transport protein.
B. Hemoglobin is an allosteric protein.
C. Hemoglobin has quaternary structure.
D. Copper ions are important in hemoglobin's ability to bind oxygen.
E. Hemoglobin is composed, in part, of an iron containing heme group.
Correct Answer: D
• Question
Which of the following would allow you to determine the isoelectric point of a protein?
A. protein quaternary structure
B. protein solubility as a function of pH
C. protein size
D. protein shape
E. protein tertiary structure
Correct Answer: B
