MICROBIOLOGY PORTAGE LEARNING MODULE 2 PRACTICE EXAM QUESTIONS COMPLETE WITH 100% VERIFIED ANSWERS AND DETAILED RATIONALE

MICROBIOLOGY PORTAGE LEARNING MODULE 2 PRACTICE EXAM QUESTIONS COMPLETE WITH 100% VERIFIED ANSWERS AND DETAILED RATIONALE 1. Which enzyme catalyzes the cleavage of chemical bonds by the addition of water? A) Ligase B) Oxidoreductase C) Hydrolase D) Lyase Correct Answer: C) Hydrolase Rationale: Hydrolase specifically catalyzes hydrolysis reactions where water is added to break chemical bonds (A-B + H2O → A-OH + B-H). ________________________________________ 2. What type of enzyme promotes intramolecular rearrangements to form isomers? A) Transferase B) Isomerase C) Lyase D) Hydrolase Correct Answer: B) Isomerase Rationale: Isomerase catalyzes the rearrangement of bonds within the same molecule to produce an isomer (A-B → B-A), maintaining the same molecular formula. ________________________________________ 3. ATP has the energy to ______, while ADP has the capacity to ______ energy. A) Accept, donate B) Donate, accept C) Store, release D) Release, store Correct Answer: B) Donate, accept Rationale: ATP (adenosine triphosphate) has energy to donate via its phosphate bonds, while ADP (adenosine diphosphate) can accept energy to be converted back to ATP. ________________________________________ 4. Which enzyme class forms covalent bonds between molecules? A) Lyase B) Hydrolase C) Ligase D) Isomerase Correct Answer: C) Ligase Rationale: Ligase catalyzes the formation of covalent bonds between molecules (A + B → A-B), joining them together. ________________________________________ 5. What is the active site of an enzyme? A) The entire surface of the enzyme B) The region that attaches to a substrate C) The area where ATP is produced D) The site of enzyme degradation Correct Answer: B) The region that attaches to a substrate Rationale: The active site is the specific region of an enzyme where substrate molecules bind and undergo a chemical reaction. ________________________________________ 6. Which enzyme cleaves bonds by means other than hydrolysis or oxidation? A) Hydrolase B) Oxidoreductase C) Ligase D) Lyase Correct Answer: D) Lyase Rationale: Lyase causes cleavage of bonds by means other than hydrolysis or oxidation (A-B → A + B), distinguishing it from hydrolases. ________________________________________ 7. Catabolism is best defined as: A) The building up of macromolecules B) The process of breaking down larger molecules into useful energy sources C) The transfer of electrons between molecules D) The rearrangement of bonds within a molecule Correct Answer: B) The process of breaking down larger molecules into useful energy sources Rationale: Catabolism involves the breakdown of larger molecules to release energy for cellular processes. ________________________________________ 8. Which enzyme transfers electrons from a reductant to an oxidant? A) Transferase B) Hydrolase C) Oxidoreductase D) Ligase