1
HESI A2 Exam Bank: 200 Questions on
Enzymes, Metabolism & Homeostasis
Table of Contents
Subtopic 1: Enzyme Structure and Function (20 Questions)............................2
Subtopic 2: Metabolic Pathways and Energy Production (20 Questions).........9
Subtopic 3: Enzyme Regulation and Feedback Mechanisms (20 Questions)..16
Subtopic 4: Homeostasis and Thermoregulation (20 Questions)...................24
Subtopic 5: Enzyme Kinetics and Clinical Applications (20 Questions)..........32
Subtopic 6: Acid-Base Balance and Metabolic Compensation (20 Questions)
.......................................................................................................................39
Subtopic 7: Hormonal Regulation and Metabolic Pathways (20 Questions)...47
Subtopic 8: Thermoregulation and Feedback Systems in Homeostasis (20
Questions)......................................................................................................54
Subtopic 9: Cellular Energy Production and Mitochondrial Function (20
Questions)......................................................................................................62
Subtopic 10: Clinical Implications of Enzyme and Metabolic Disorders (20
Questions)......................................................................................................69
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Subtopic 1: Enzyme Structure and Function
(20 Questions)
1. What is the primary function of enzymes in biological systems?
A. Store genetic information
B. Speed up chemical reactions
C. Act as structural components
D. Transport oxygen
Correct Answer: B. Speed up chemical reactions
Rationale: Enzymes act as biological catalysts that increase the rate of
biochemical reactions by lowering activation energy, which is essential in
metabolic processes.
2. Which component of an enzyme is directly involved in the catalytic
reaction?
A. Substrate
B. Active site
C. Coenzyme
D. Allosteric site
Correct Answer: B. Active site
Rationale: The active site is the region of the enzyme where substrate
molecules bind and undergo a chemical reaction.
3. What happens to an enzyme after it catalyzes a reaction?
A. It is destroyed
B. It is absorbed by the substrate
, 3
C. It becomes a product
D. It remains unchanged and can be reused
Correct Answer: D. It remains unchanged and can be reused
Rationale: Enzymes are not consumed in reactions; they remain unchanged
and can participate in multiple reaction cycles.
4. How does temperature generally affect enzyme activity?
A. It has no effect
B. It increases activity to a point, then denatures the enzyme
C. It decreases activity permanently
D. It breaks down the substrate
Correct Answer: B. It increases activity to a point, then denatures the enzyme
Rationale: Enzyme activity increases with temperature up to an optimal
point. Beyond that, enzymes denature and lose functionality.
5. Which term describes an enzyme’s ability to bind only specific substrates?
A. Polarity
B. Specificity
C. Saturation
D. Affinity
Correct Answer: B. Specificity
Rationale: Enzymes are highly specific, meaning they only catalyze reactions
with particular substrates due to the shape of their active site.
6. What is a coenzyme?
, 4
A. A substrate that binds reversibly
B. A denatured protein
C. A non-protein organic molecule that assists enzymes
D. A product of enzyme catalysis
Correct Answer: C. A non-protein organic molecule that assists enzymes
Rationale: Coenzymes, like vitamins, help enzymes function by stabilizing
reactions or aiding in substrate transformation.
7. Which factor does not influence enzyme activity?
A. pH
B. Temperature
C. Substrate concentration
D. Genetic code
Correct Answer: D. Genetic code
Rationale: While genes code for enzyme synthesis, the genetic code itself
doesn't directly influence enzyme activity once the enzyme is made.
8. An enzyme with a missing cofactor will likely be:
A. Hyperactive
B. Overproduced
C. Inactive
D. Degraded
Correct Answer: C. Inactive
Rationale: Many enzymes require cofactors to be functional. Without them,
the enzyme cannot catalyze reactions effectively.
HESI A2 Exam Bank: 200 Questions on
Enzymes, Metabolism & Homeostasis
Table of Contents
Subtopic 1: Enzyme Structure and Function (20 Questions)............................2
Subtopic 2: Metabolic Pathways and Energy Production (20 Questions).........9
Subtopic 3: Enzyme Regulation and Feedback Mechanisms (20 Questions)..16
Subtopic 4: Homeostasis and Thermoregulation (20 Questions)...................24
Subtopic 5: Enzyme Kinetics and Clinical Applications (20 Questions)..........32
Subtopic 6: Acid-Base Balance and Metabolic Compensation (20 Questions)
.......................................................................................................................39
Subtopic 7: Hormonal Regulation and Metabolic Pathways (20 Questions)...47
Subtopic 8: Thermoregulation and Feedback Systems in Homeostasis (20
Questions)......................................................................................................54
Subtopic 9: Cellular Energy Production and Mitochondrial Function (20
Questions)......................................................................................................62
Subtopic 10: Clinical Implications of Enzyme and Metabolic Disorders (20
Questions)......................................................................................................69
, 2
Subtopic 1: Enzyme Structure and Function
(20 Questions)
1. What is the primary function of enzymes in biological systems?
A. Store genetic information
B. Speed up chemical reactions
C. Act as structural components
D. Transport oxygen
Correct Answer: B. Speed up chemical reactions
Rationale: Enzymes act as biological catalysts that increase the rate of
biochemical reactions by lowering activation energy, which is essential in
metabolic processes.
2. Which component of an enzyme is directly involved in the catalytic
reaction?
A. Substrate
B. Active site
C. Coenzyme
D. Allosteric site
Correct Answer: B. Active site
Rationale: The active site is the region of the enzyme where substrate
molecules bind and undergo a chemical reaction.
3. What happens to an enzyme after it catalyzes a reaction?
A. It is destroyed
B. It is absorbed by the substrate
, 3
C. It becomes a product
D. It remains unchanged and can be reused
Correct Answer: D. It remains unchanged and can be reused
Rationale: Enzymes are not consumed in reactions; they remain unchanged
and can participate in multiple reaction cycles.
4. How does temperature generally affect enzyme activity?
A. It has no effect
B. It increases activity to a point, then denatures the enzyme
C. It decreases activity permanently
D. It breaks down the substrate
Correct Answer: B. It increases activity to a point, then denatures the enzyme
Rationale: Enzyme activity increases with temperature up to an optimal
point. Beyond that, enzymes denature and lose functionality.
5. Which term describes an enzyme’s ability to bind only specific substrates?
A. Polarity
B. Specificity
C. Saturation
D. Affinity
Correct Answer: B. Specificity
Rationale: Enzymes are highly specific, meaning they only catalyze reactions
with particular substrates due to the shape of their active site.
6. What is a coenzyme?
, 4
A. A substrate that binds reversibly
B. A denatured protein
C. A non-protein organic molecule that assists enzymes
D. A product of enzyme catalysis
Correct Answer: C. A non-protein organic molecule that assists enzymes
Rationale: Coenzymes, like vitamins, help enzymes function by stabilizing
reactions or aiding in substrate transformation.
7. Which factor does not influence enzyme activity?
A. pH
B. Temperature
C. Substrate concentration
D. Genetic code
Correct Answer: D. Genetic code
Rationale: While genes code for enzyme synthesis, the genetic code itself
doesn't directly influence enzyme activity once the enzyme is made.
8. An enzyme with a missing cofactor will likely be:
A. Hyperactive
B. Overproduced
C. Inactive
D. Degraded
Correct Answer: C. Inactive
Rationale: Many enzymes require cofactors to be functional. Without them,
the enzyme cannot catalyze reactions effectively.
