CHEM 210 Biochemistry Final Exam 1
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
globular protein?
A) Serine
B) Lysine
C) Glutamate
D) Valine
Valine is nonpolar and hydrophobic, so it prefers the interior of
proteins away from aqueous environments.
2. Which type of bond stabilizes α-helices and β-sheets?
A) Ionic bonds
B) Disulfide bonds
C) Hydrogen bonds
, D) Hydrophobic interactions
Hydrogen bonds form between backbone amide and carbonyl
groups, stabilizing secondary structures.
3. What is the net charge of glutamic acid at pH 7?
A) +1
B) 0
C) -1
D) -2
Glutamic acid has a carboxyl side chain that is deprotonated at pH 7,
giving it a negative charge.
4. Which enzyme catalyzes the phosphorylation of glucose?
A) Glucose-6-phosphatase
B) Aldolase
C) Hexokinase
D) Pyruvate kinase
Hexokinase adds a phosphate to glucose, forming glucose-6-
phosphate in glycolysis.
5. Which vitamin is required for the synthesis of NAD+?
A) Vitamin C
B) Vitamin D
C) Niacin
D) Thiamine
Niacin (vitamin B3) is a precursor for NAD+ and NADP+.
,6. Which metabolic pathway occurs exclusively in the mitochondria?
A) Glycolysis
B) TCA cycle
C) Pentose phosphate pathway
D) Fatty acid synthesis
The TCA cycle occurs entirely within the mitochondrial matrix.
7. Which molecule donates electrons directly to the electron transport
chain complex I?
A) NADH
B) FADH2
C) ATP
D) Pyruvate
NADH donates electrons to complex I (NADH dehydrogenase).
8. Which amino acid is the main nitrogen donor in transamination
reactions?
A) Lysine
B) Glutamate
C) Alanine
D) Glycine
Glutamate commonly donates its amino group during
transamination.
9. Which of the following is an essential amino acid?
A) Leucine
, B) Tyrosine
C) Glutamine
D) Cysteine
Leucine must be obtained from the diet because humans cannot
synthesize it.
10. Which enzyme is defective in phenylketonuria (PKU)?
A) Tyrosinase
B) Phenylalanine hydroxylase
C) Dopamine hydroxylase
D) Homogentisate oxidase
A defect in phenylalanine hydroxylase prevents conversion of
phenylalanine to tyrosine.
11. Which bond connects monosaccharides in disaccharides?
A) Peptide bond
B) Phosphodiester bond
C) Disulfide bond
D) Glycosidic bond
Monosaccharides are linked by glycosidic bonds in disaccharides.
12. Which is the major storage form of carbohydrates in animals?
A) Cellulose
B) Glycogen
C) Amylose
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
globular protein?
A) Serine
B) Lysine
C) Glutamate
D) Valine
Valine is nonpolar and hydrophobic, so it prefers the interior of
proteins away from aqueous environments.
2. Which type of bond stabilizes α-helices and β-sheets?
A) Ionic bonds
B) Disulfide bonds
C) Hydrogen bonds
, D) Hydrophobic interactions
Hydrogen bonds form between backbone amide and carbonyl
groups, stabilizing secondary structures.
3. What is the net charge of glutamic acid at pH 7?
A) +1
B) 0
C) -1
D) -2
Glutamic acid has a carboxyl side chain that is deprotonated at pH 7,
giving it a negative charge.
4. Which enzyme catalyzes the phosphorylation of glucose?
A) Glucose-6-phosphatase
B) Aldolase
C) Hexokinase
D) Pyruvate kinase
Hexokinase adds a phosphate to glucose, forming glucose-6-
phosphate in glycolysis.
5. Which vitamin is required for the synthesis of NAD+?
A) Vitamin C
B) Vitamin D
C) Niacin
D) Thiamine
Niacin (vitamin B3) is a precursor for NAD+ and NADP+.
,6. Which metabolic pathway occurs exclusively in the mitochondria?
A) Glycolysis
B) TCA cycle
C) Pentose phosphate pathway
D) Fatty acid synthesis
The TCA cycle occurs entirely within the mitochondrial matrix.
7. Which molecule donates electrons directly to the electron transport
chain complex I?
A) NADH
B) FADH2
C) ATP
D) Pyruvate
NADH donates electrons to complex I (NADH dehydrogenase).
8. Which amino acid is the main nitrogen donor in transamination
reactions?
A) Lysine
B) Glutamate
C) Alanine
D) Glycine
Glutamate commonly donates its amino group during
transamination.
9. Which of the following is an essential amino acid?
A) Leucine
, B) Tyrosine
C) Glutamine
D) Cysteine
Leucine must be obtained from the diet because humans cannot
synthesize it.
10. Which enzyme is defective in phenylketonuria (PKU)?
A) Tyrosinase
B) Phenylalanine hydroxylase
C) Dopamine hydroxylase
D) Homogentisate oxidase
A defect in phenylalanine hydroxylase prevents conversion of
phenylalanine to tyrosine.
11. Which bond connects monosaccharides in disaccharides?
A) Peptide bond
B) Phosphodiester bond
C) Disulfide bond
D) Glycosidic bond
Monosaccharides are linked by glycosidic bonds in disaccharides.
12. Which is the major storage form of carbohydrates in animals?
A) Cellulose
B) Glycogen
C) Amylose
