,CHEM 210 Module 7 Exam | Biochemistry |
Portage Learning | Q & A | 2026 Edition
1. Which of the following best defines the term "flux" in the context of a biochemical pathway?
A) The total amount of substrate present in a cell at any given time
B) The rate of flow through a biochemical pathway
C) The number of enzymes required to complete a pathway
D) The energy released during a metabolic reaction
Correct Answer: The rate of flow through a biochemical pathway
Rationale: Flux in biochemistry refers to the rate at which metabolites flow through a metabolic
pathway. It is determined by the activity of enzymes and the concentrations of substrates and products.
Flux is a dynamic measure that reflects the overall throughput of a pathway.
2. What is the primary difference between a catabolic and an anabolic pathway?
A) Catabolic pathways synthesize complex molecules; anabolic pathways break them down
B) Catabolic pathways break down complex molecules; anabolic pathways synthesize them
C) Catabolic pathways require energy; anabolic pathways release energy
D) Catabolic pathways occur only in mitochondria; anabolic pathways occur only in the cytosol
Correct Answer: Catabolic pathways break down complex molecules; anabolic pathways synthesize
them
Rationale: Catabolic pathways degrade complex molecules into simpler ones, releasing energy (e.g.,
glycolysis, β-oxidation). Anabolic pathways build complex molecules from simpler precursors, consuming
energy. Both types are essential for cellular metabolism and homeostasis.
3. According to the module, what are the three basic phases of breaking down glucose?
A) Glycolysis, fermentation, and oxidative phosphorylation
,B) Glycolysis, citric acid cycle, and electron transport chain
C) Glycolysis, gluconeogenesis, and the pentose phosphate pathway
D) Glycolysis, the Cori cycle, and the urea cycle
Correct Answer: Glycolysis, citric acid cycle, and electron transport chain
Rationale: Glucose breakdown occurs in three main phases: glycolysis (glucose → pyruvate), the citric
acid cycle (acetyl-CoA oxidation), and the electron transport chain (NADH and FADH₂ oxidation coupled
to ATP synthesis). These phases progressively extract energy from glucose.
4. What does a negative ΔG value indicate about a biochemical reaction?
A) The reaction is non-spontaneous and requires energy input
B) The reaction is spontaneous and thermodynamically favorable
C) The reaction is at equilibrium
D) The reaction will proceed in the reverse direction
Correct Answer: The reaction is spontaneous and thermodynamically favorable
Rationale: A negative ΔG indicates that a reaction is exergonic and spontaneous, meaning it can proceed
without external energy input. This energy release can be harnessed to drive cellular processes. The sign
of ΔG is critical for understanding metabolic directionality.
5. Which of the following correctly describes a biochemical metabolic pathway?
A) A single reaction that converts starting material directly into products
B) A series of enzymatic reactions where the product of one becomes the substrate of the next
C) A process that occurs only in the presence of oxygen
D) A pathway that always produces ATP
Correct Answer: A series of enzymatic reactions where the product of one becomes the substrate of the
next
, Rationale: A biochemical metabolic pathway is a sequence of enzyme-catalyzed reactions, each
converting a substrate into a product that serves as the substrate for the next reaction. Pathways are
highly regulated and allow for precise control of cellular metabolism.
6. Where in the cell does glycolysis take place?
A) Mitochondria
B) Cytosol
C) Nucleus
D) Endoplasmic reticulum
Correct Answer: Cytosol
Rationale: Glycolysis occurs in the cytosol of the cell, where the enzymes for glucose breakdown are
located. This location allows glycolysis to function independently of oxygen and provides rapid ATP
generation in all cells.
7. How many ATP molecules are invested (used) in the energy-investing stage of glycolysis?
A) 1
B) 2
C) 3
D) 4
Correct Answer: 2
Rationale: Two ATP molecules are invested in the preparatory phase of glycolysis to phosphorylate
glucose and fructose-6-phosphate. This investment is required to activate glucose and facilitate its
cleavage into two three-carbon molecules.
8. What is the net number of ATP molecules gained from glycolysis per molecule of glucose?
A) 1
Portage Learning | Q & A | 2026 Edition
1. Which of the following best defines the term "flux" in the context of a biochemical pathway?
A) The total amount of substrate present in a cell at any given time
B) The rate of flow through a biochemical pathway
C) The number of enzymes required to complete a pathway
D) The energy released during a metabolic reaction
Correct Answer: The rate of flow through a biochemical pathway
Rationale: Flux in biochemistry refers to the rate at which metabolites flow through a metabolic
pathway. It is determined by the activity of enzymes and the concentrations of substrates and products.
Flux is a dynamic measure that reflects the overall throughput of a pathway.
2. What is the primary difference between a catabolic and an anabolic pathway?
A) Catabolic pathways synthesize complex molecules; anabolic pathways break them down
B) Catabolic pathways break down complex molecules; anabolic pathways synthesize them
C) Catabolic pathways require energy; anabolic pathways release energy
D) Catabolic pathways occur only in mitochondria; anabolic pathways occur only in the cytosol
Correct Answer: Catabolic pathways break down complex molecules; anabolic pathways synthesize
them
Rationale: Catabolic pathways degrade complex molecules into simpler ones, releasing energy (e.g.,
glycolysis, β-oxidation). Anabolic pathways build complex molecules from simpler precursors, consuming
energy. Both types are essential for cellular metabolism and homeostasis.
3. According to the module, what are the three basic phases of breaking down glucose?
A) Glycolysis, fermentation, and oxidative phosphorylation
,B) Glycolysis, citric acid cycle, and electron transport chain
C) Glycolysis, gluconeogenesis, and the pentose phosphate pathway
D) Glycolysis, the Cori cycle, and the urea cycle
Correct Answer: Glycolysis, citric acid cycle, and electron transport chain
Rationale: Glucose breakdown occurs in three main phases: glycolysis (glucose → pyruvate), the citric
acid cycle (acetyl-CoA oxidation), and the electron transport chain (NADH and FADH₂ oxidation coupled
to ATP synthesis). These phases progressively extract energy from glucose.
4. What does a negative ΔG value indicate about a biochemical reaction?
A) The reaction is non-spontaneous and requires energy input
B) The reaction is spontaneous and thermodynamically favorable
C) The reaction is at equilibrium
D) The reaction will proceed in the reverse direction
Correct Answer: The reaction is spontaneous and thermodynamically favorable
Rationale: A negative ΔG indicates that a reaction is exergonic and spontaneous, meaning it can proceed
without external energy input. This energy release can be harnessed to drive cellular processes. The sign
of ΔG is critical for understanding metabolic directionality.
5. Which of the following correctly describes a biochemical metabolic pathway?
A) A single reaction that converts starting material directly into products
B) A series of enzymatic reactions where the product of one becomes the substrate of the next
C) A process that occurs only in the presence of oxygen
D) A pathway that always produces ATP
Correct Answer: A series of enzymatic reactions where the product of one becomes the substrate of the
next
, Rationale: A biochemical metabolic pathway is a sequence of enzyme-catalyzed reactions, each
converting a substrate into a product that serves as the substrate for the next reaction. Pathways are
highly regulated and allow for precise control of cellular metabolism.
6. Where in the cell does glycolysis take place?
A) Mitochondria
B) Cytosol
C) Nucleus
D) Endoplasmic reticulum
Correct Answer: Cytosol
Rationale: Glycolysis occurs in the cytosol of the cell, where the enzymes for glucose breakdown are
located. This location allows glycolysis to function independently of oxygen and provides rapid ATP
generation in all cells.
7. How many ATP molecules are invested (used) in the energy-investing stage of glycolysis?
A) 1
B) 2
C) 3
D) 4
Correct Answer: 2
Rationale: Two ATP molecules are invested in the preparatory phase of glycolysis to phosphorylate
glucose and fructose-6-phosphate. This investment is required to activate glucose and facilitate its
cleavage into two three-carbon molecules.
8. What is the net number of ATP molecules gained from glycolysis per molecule of glucose?
A) 1
