| Portage Learning | Q & A | 2026 Edition
1. Which of the following best describes the overall definition of cellular metabolism?
A) The breakdown of glucose to produce ATP
B) The synthesis of macromolecules from smaller subunits
C) A controlled set of biochemical reactions that occur in living organisms to maintain life
D) The process of converting light energy into chemical energy
Correct Answer: A controlled set of biochemical reactions that occur in living organisms to maintain life
Rationale: Metabolism is defined as the controlled set of biochemical reactions that occur in living
organisms to maintain life. Options A and B describe specific types of metabolic reactions (catabolism
and anabolism), while D describes photosynthesis.
2. What is the primary function of enzymes in a cell?
A) To slow down chemical reactions to conserve energy
B) To speed up (catalyze) chemical reactions
C) To provide structural support to the cell
D) To store genetic information
Correct Answer: To speed up (catalyze) chemical reactions
Rationale: Enzymes are biological catalysts that speed up chemical reactions. They lower activation
energy and are not consumed in the reaction, allowing them to be used repeatedly.
3. The term for metal ions that assist enzymes during catalysis reactions is:
A) Active site
B) Cofactor
C) Substrate
,D) Coenzyme
Correct Answer: Cofactor
Rationale: A cofactor is a non-protein chemical compound that assists an enzyme during catalysis. Metal
ions are common examples of cofactors.
4. What is catabolism?
A) The synthesis of complex molecules from simpler ones
B) The process of breaking down larger molecules into smaller ones to release energy
C) The storage of genetic information
D) The transport of molecules across a membrane
Correct Answer: The process of breaking down larger molecules into smaller ones to release energy
Rationale: Catabolism is the breakdown of complex molecules into smaller molecules, releasing energy
in the process. It is the opposite of anabolism, which builds molecules up.
5. Upon cellular injury, which metabolic process is primarily involved during the growth and repair
phases of the cell?
A) Catabolism
B) Fermentation
C) Anabolism
D) Glycolysis
Correct Answer: Anabolism
Rationale: Anabolism is the biosynthesis of macromolecules from smaller units and is associated with
cellular growth and repair. Catabolism breaks down molecules, while fermentation and glycolysis are
energy-generating pathways.
, 6. An organism that obtains its energy (derives ATP) from photons of light is called a:
A) Chemotroph
B) Lithotroph
C) Phototroph
D) Organotroph
Correct Answer: Phototroph
Rationale: Phototrophic microorganisms derive their energy from light (photons). Chemotrophs get
energy from chemicals, and lithotrophs specifically get energy from inorganic substances.
7. An organism that derives its energy by removing electrons from elemental sulfur would be classified
as a:
A) Phototroph
B) Organotroph
C) Chemotroph
D) Lithotroph
Correct Answer: Lithotroph
Rationale: Lithotrophs are organisms that derive energy by removing electrons from inorganic
substances, such as elemental sulfur. Organotrophs remove electrons from organic molecules.
8. Describe the energy transfer process relative to both ADP and ATP.
A) ATP accepts a phosphate group to become ADP
B) ADP donates a phosphate group to become ATP
C) ATP has energy to donate (becoming ADP + Pi), while ADP can accept energy (becoming ATP)
D) Both ATP and ADP can accept and donate phosphate groups equally