MCQ Collection
MDCAT 2026 MCQs
Practice MDCAT 2026 questions with answers and explanations.
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Correct Answer: D. An inhibitor binds away from the active site and changes enzyme activity
Explanation:
Noncompetitive binding changes enzyme shape or function.
Adding more substrate does not fully overcome it.
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Correct Answer: A. Region where the substrate binds and reaction occurs
Explanation:
The active site has a shape and chemistry suited to its substrate.
Binding promotes the transition state.
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Correct Answer: A. An inhibitor binds away from the active site and changes enzyme activity
Explanation:
Noncompetitive binding changes enzyme shape or function.
Adding more substrate does not fully overcome it.
Choose an option to check your answer.
Correct Answer: B. Region where the substrate binds and reaction occurs
Explanation:
The active site has a shape and chemistry suited to its substrate.
Binding promotes the transition state.
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Correct Answer: B. The cell's main immediate energy-transfer molecule
Explanation:
ATP stores usable energy in phosphate bonds.
Hydrolysis of ATP powers many cellular processes.
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Correct Answer: C. The reactant acted upon by an enzyme
Explanation:
Substrates bind to active sites.
They are converted into products during the reaction.
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Correct Answer: C. The cell's main immediate energy-transfer molecule
Explanation:
ATP stores usable energy in phosphate bonds.
Hydrolysis of ATP powers many cellular processes.
Choose an option to check your answer.
Correct Answer: D. The reactant acted upon by an enzyme
Explanation:
Substrates bind to active sites.
They are converted into products during the reaction.
Choose an option to check your answer.
Correct Answer: D. The cell's main immediate energy-transfer molecule
Explanation:
ATP stores usable energy in phosphate bonds.
Hydrolysis of ATP powers many cellular processes.
Choose an option to check your answer.
Correct Answer: A. The reactant acted upon by an enzyme
Explanation:
Substrates bind to active sites.
They are converted into products during the reaction.
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Correct Answer: A. Cytoplasm
Explanation:
Glycolysis breaks glucose into pyruvate.
It occurs in the cytosol and does not directly require oxygen.
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Correct Answer: B. Activity rises to an optimum and then may fall as the enzyme denatures
Explanation:
Warming increases molecular collisions up to an optimum.
Excess heat disrupts enzyme structure.
