Free Enzymes MCQs with Answers
633 Enzymes MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Enzymes are biological catalysts that lower activation energy without being consumed, and their specificity is explained by the lock and key and induced fit models. Work includes the effects of temperature, pH and substrate concentration on reaction rate, plus competitive and non-competitive inhibition and how these differ.
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Read the Enzymes notesFree MDCAT chapter notes with key terms633 questions · page 32 of 32
- A. Coenzymes
- B. Activators
- C. Prosthetic group
- D. Apoenzyme
Explanation: Activators are inorganic ions that bind to enzymes and play a crucial role in enzyme activity.
Correct answer: Activators- A. Non-competitive
- B. Competitive
- C. Irreversible
- D. Isosteric
Explanation: In noncompetitive inhibition, the inhibitor binds at an allosteric site separate from the active site of substrate binding.
Correct answer: Non-competitive- A. 3.00
- B. 4.50
- C. 2.00
- D. 6.00
Explanation: Pepsin works best at a pH of around 2.00, which is highly acidic. The low pH helps denature proteins and allows pepsin to cleave peptide…
Correct answer: 2.00- A. Products
- B. Metabolites
- C. Substrates
- D. Catabolites
Explanation: Enzymes work by acting on substrates and converting them into products.
Correct answer: Substrates- A. Coenzyme
- B. Apoenzyme
- C. Holoenzyme
- D. Denatured enzyme
Explanation: The correct answer is apoenzyme. An apoenzyme is the protein part of an enzyme that is inactive on its own.
Correct answer: Apoenzyme- A. They increase the activation energy
- B. They are specific in action
- C. They possess specific active site
- D. They possess dimensional shapes
Explanation: They increase the activation energy: This statement is incorrect. Enzymes actually decrease the activation energy required for a chemical…
Correct answer: They increase the activation energy- A. Proteins
- B. Carbohydrates
- C. Hydrocarbons
- D. None of the above
Explanation: Enzymes are specialized proteins that catalyze biochemical reactions, enabling them to occur more rapidly and efficiently.
Correct answer: Proteins- A. NAD
- B. FAD
- C. NADP
- D. ADP
Explanation: Coenzymes are non-protein, organic compounds required by many enzymes for catalytic activity.
Correct answer: ADP- A. Protien
- B. Urea
- C. Lipid
- D. ATP
Explanation: Lipase is an enzyme that helps break down lipids, which are fats and oils.
Correct answer: Lipid- A. Specific Temperature
- B. Specific pH
- C. Specific Co-enzyme
- D. All the above
Explanation: The correct answer is 'All the above' because enzymes require specific conditions to function at their best.
Correct answer: All the above- A. 4.5
- B. 5.5
- C. 6.1 - 6.8
- D. 6.7 - 7
Explanation: Maltase is an enzyme that catalyzes the hydrolysis of the disaccharide maltose to the simple sugar glucose.
Correct answer: 6.1 - 6.8- A. Substrate concentration
- B. pH
- C. Enzyme concentration
- D. Temperaturep
Explanation: Substrate concentration refers to the amount of substrate present in a chemical reaction.
Correct answer: Substrate concentration- A. 3
- B. 3.5
- C. 2
- D. 2.5
Explanation: The stomach contains gastric glands that secrete hydrochloric acid (HCl) along with pepsinogen, an inactive precursor of pepsin.
Correct answer: 2