BIOL 271 MODULE 5 EXAM:
MICROBIAL METABOLISM EXAM
QUESTIONS AND ANSWERS
1. Which of the following best describes the ‘activation energy’ of a chemical reaction?
A. The energy required to destabilize chemical bonds and initiate a reaction.
B. The total energy released by an exergonic reaction.
C. The energy stored within the phosphate bonds of ATP.
D. The difference in energy between the reactants and the products.
Answer: A
Conceptual Explanation: Activation energy is the minimum amount of energy needed for
a chemical reaction to occur by breaking or weakening initial chemical bonds.
2. An enzyme-substrate complex forms when a substrate binds to which specific region of an
enzyme?
A. Allosteric site
B. Cofactor binding site
C. Active site
D. Apoenzyme surface
,Answer: C
Conceptual Explanation: The active site is the specific region of the enzyme where the
substrate binds and the chemical reaction is catalyzed.
3. What is the term for a non-protein organic molecule that assists an enzyme in its catalytic
activity?
A. Cofactor
B. Coenzyme
C. Holoenzyme
D. Apoenzyme
Answer: B
Conceptual Explanation: Coenzymes are organic molecules (like NAD+ or FAD) that act as
cofactors; cofactors can be inorganic (metal ions) or organic.
4. In competitive inhibition, where does the inhibitor bind?
A. To the allosteric site
B. To the enzyme-substrate complex
C. To the substrate itself
D. Directly to the active site
Answer: D
, Conceptual Explanation: Competitive inhibitors mimic the substrate and compete for
binding at the active site.
5. Which metabolic process involves the breakdown of complex organic compounds into
simpler ones, releasing energy?
A. Anabolism
B. Photosynthesis
C. Catabolism
D. Biosynthesis
Answer: C
Conceptual Explanation: Catabolism refers to exergonic pathways that break down
molecules to provide energy and building blocks for anabolism.
6. ATP is often referred to as the energy currency of the cell. Which part of the ATP molecule
stores the most accessible energy?
A. The ribose sugar
B. The bonds between phosphate groups
C. The adenine base
D. The carbon-hydrogen bonds
Answer: B
MICROBIAL METABOLISM EXAM
QUESTIONS AND ANSWERS
1. Which of the following best describes the ‘activation energy’ of a chemical reaction?
A. The energy required to destabilize chemical bonds and initiate a reaction.
B. The total energy released by an exergonic reaction.
C. The energy stored within the phosphate bonds of ATP.
D. The difference in energy between the reactants and the products.
Answer: A
Conceptual Explanation: Activation energy is the minimum amount of energy needed for
a chemical reaction to occur by breaking or weakening initial chemical bonds.
2. An enzyme-substrate complex forms when a substrate binds to which specific region of an
enzyme?
A. Allosteric site
B. Cofactor binding site
C. Active site
D. Apoenzyme surface
,Answer: C
Conceptual Explanation: The active site is the specific region of the enzyme where the
substrate binds and the chemical reaction is catalyzed.
3. What is the term for a non-protein organic molecule that assists an enzyme in its catalytic
activity?
A. Cofactor
B. Coenzyme
C. Holoenzyme
D. Apoenzyme
Answer: B
Conceptual Explanation: Coenzymes are organic molecules (like NAD+ or FAD) that act as
cofactors; cofactors can be inorganic (metal ions) or organic.
4. In competitive inhibition, where does the inhibitor bind?
A. To the allosteric site
B. To the enzyme-substrate complex
C. To the substrate itself
D. Directly to the active site
Answer: D
, Conceptual Explanation: Competitive inhibitors mimic the substrate and compete for
binding at the active site.
5. Which metabolic process involves the breakdown of complex organic compounds into
simpler ones, releasing energy?
A. Anabolism
B. Photosynthesis
C. Catabolism
D. Biosynthesis
Answer: C
Conceptual Explanation: Catabolism refers to exergonic pathways that break down
molecules to provide energy and building blocks for anabolism.
6. ATP is often referred to as the energy currency of the cell. Which part of the ATP molecule
stores the most accessible energy?
A. The ribose sugar
B. The bonds between phosphate groups
C. The adenine base
D. The carbon-hydrogen bonds
Answer: B
