CHEM 210 Biochemistry Final Exam 2
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2025
Q&A | Instant Download PDF
1. Which amino acid is most likely to be found in the interior of a soluble
globular protein?
A) Lysine
B) Glutamate
C) Valine
D) Arginine
Answer: C
Valine is nonpolar and hydrophobic, favoring the interior of a
globular protein to avoid water.
2. The peptide bond is:
A) A hydrogen bond
B) An ionic bond
, C) A covalent bond
D) A Van der Waals interaction
Answer: C
The peptide bond is a covalent amide linkage formed between the
carboxyl group of one amino acid and the amino group of another.
3. Which level of protein structure is characterized by alpha helices and
beta sheets?
A) Primary
B) Secondary
C) Tertiary
D) Quaternary
Answer: B
Secondary structure refers to local folding such as alpha helices and
beta sheets stabilized by hydrogen bonds.
4. Which of the following best describes an enzyme’s active site?
A) A rigid structure
B) The same shape for all substrates
C) Highly specific for its substrate
D) Composed only of metal ions
Answer: C
The active site is specifically shaped to bind its substrate(s) precisely.
5. What is the effect of a noncompetitive inhibitor on Vmax and Km?
A) Vmax decreases, Km unchanged
, B) Vmax increases, Km increases
C) Vmax unchanged, Km decreases
D) Vmax decreases, Km increases
Answer: A
Noncompetitive inhibitors lower Vmax because they bind away from
the active site, but Km stays the same since substrate binding affinity
is unchanged.
6. Which vitamin is a precursor for NAD+?
A) Vitamin B1
B) Vitamin B2
C) Vitamin B3
D) Vitamin B12
Answer: C
Vitamin B3 (niacin) is used to synthesize NAD+ and NADP+.
7. The main product of glycolysis is:
A) Acetyl-CoA
B) Glucose
C) Pyruvate
D) Citrate
Answer: C
Glycolysis converts glucose to two molecules of pyruvate.
8. Which enzyme catalyzes the rate-limiting step of glycolysis?
A) Hexokinase
, B) Phosphofructokinase-1
C) Pyruvate kinase
D) Lactate dehydrogenase
Answer: B
Phosphofructokinase-1 is the major regulatory enzyme and commits
glucose to glycolysis.
9. Which pathway occurs entirely in the cytoplasm?
A) Citric acid cycle
B) Glycolysis
C) Beta oxidation
D) Electron transport chain
Answer: B
Glycolysis takes place in the cytoplasm.
10. Which coenzyme is required for pyruvate dehydrogenase
complex?
A) NADPH
B) FADH2
C) TPP (thiamine pyrophosphate)
D) Biotin
Answer: C
TPP, derived from vitamin B1, is essential for decarboxylation of
pyruvate.
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2025
Q&A | Instant Download PDF
1. Which amino acid is most likely to be found in the interior of a soluble
globular protein?
A) Lysine
B) Glutamate
C) Valine
D) Arginine
Answer: C
Valine is nonpolar and hydrophobic, favoring the interior of a
globular protein to avoid water.
2. The peptide bond is:
A) A hydrogen bond
B) An ionic bond
, C) A covalent bond
D) A Van der Waals interaction
Answer: C
The peptide bond is a covalent amide linkage formed between the
carboxyl group of one amino acid and the amino group of another.
3. Which level of protein structure is characterized by alpha helices and
beta sheets?
A) Primary
B) Secondary
C) Tertiary
D) Quaternary
Answer: B
Secondary structure refers to local folding such as alpha helices and
beta sheets stabilized by hydrogen bonds.
4. Which of the following best describes an enzyme’s active site?
A) A rigid structure
B) The same shape for all substrates
C) Highly specific for its substrate
D) Composed only of metal ions
Answer: C
The active site is specifically shaped to bind its substrate(s) precisely.
5. What is the effect of a noncompetitive inhibitor on Vmax and Km?
A) Vmax decreases, Km unchanged
, B) Vmax increases, Km increases
C) Vmax unchanged, Km decreases
D) Vmax decreases, Km increases
Answer: A
Noncompetitive inhibitors lower Vmax because they bind away from
the active site, but Km stays the same since substrate binding affinity
is unchanged.
6. Which vitamin is a precursor for NAD+?
A) Vitamin B1
B) Vitamin B2
C) Vitamin B3
D) Vitamin B12
Answer: C
Vitamin B3 (niacin) is used to synthesize NAD+ and NADP+.
7. The main product of glycolysis is:
A) Acetyl-CoA
B) Glucose
C) Pyruvate
D) Citrate
Answer: C
Glycolysis converts glucose to two molecules of pyruvate.
8. Which enzyme catalyzes the rate-limiting step of glycolysis?
A) Hexokinase
, B) Phosphofructokinase-1
C) Pyruvate kinase
D) Lactate dehydrogenase
Answer: B
Phosphofructokinase-1 is the major regulatory enzyme and commits
glucose to glycolysis.
9. Which pathway occurs entirely in the cytoplasm?
A) Citric acid cycle
B) Glycolysis
C) Beta oxidation
D) Electron transport chain
Answer: B
Glycolysis takes place in the cytoplasm.
10. Which coenzyme is required for pyruvate dehydrogenase
complex?
A) NADPH
B) FADH2
C) TPP (thiamine pyrophosphate)
D) Biotin
Answer: C
TPP, derived from vitamin B1, is essential for decarboxylation of
pyruvate.
