Enzymes MCQs (Quiz 8)By guishaqasif / April 29, 2026 1. Repression of enzyme synthesis in metabolic pathways is primarily caused by _______ Cofactor availability End product Enzyme concentration Substrate accumulation 2. The region of an enzyme where substrate binds is called _______ Binding domain Active site Catalytic core Allosteric site 3. How many genes typically encode the synthesis of a single enzyme (polypeptide chain)? Four One Eight Sixteen 4. Chitin, a structural substrate degraded by the enzyme chitinase, is classified as a _______ Sulphur-containing polysaccharide Simple polysaccharide composed only of glucose units Phosphorus-containing polysaccharide Nitrogen-containing polysaccharide 5. In prokaryotes, repression of enzyme synthesis commonly involves _______ RNA editing Enhancers Operon systems Splicing 6. Which enzyme was first successfully isolated and crystallized, demonstrating that enzymes are proteins? Pepsin Amylase Ribonuclease Urease 7. Which of the following statements regarding enzyme action is INCORRECT? Malonate acts as a competitive inhibitor of succinate dehydrogenase Substrate binds to the enzyme at its active site Addition of excess succinate does not reverse malonate inhibition Non-competitive inhibitors bind at a site other than the active site 8. The induced-fit model suggests that enzymes are _______ Inactive before binding Independent of substrate Flexible and adapt to substrate binding Rigid structures 9. Enzyme-driven metabolic pathways become more efficient by ____________ Grouping enzymes into multienzyme complexes Localizing enzymes in specific cellular compartments All of these Fixing enzymes into membranes close to each other 10. A corepressor functions by _______ Binding to a repressor protein and activating it to inhibit transcription Increasing substrate affinity of enzymes Enhancing transcription of structural genes Directly destroying the enzyme Loading … Question 1 of 10
