Introduction to Metabolism

  1. All of the following statements regarding enzymes are true EXCEPT:
    A) Enzymes allow molecules to react in metabolism by lowering activation energies.
    B) Enzymes are very sensitive to environmental conditions that influence the weak chemical bonds responsible for their three-dimensional structure.
    C) Some enzymes change shape when regulator molecules, either activators or inhibitors, bind to specific allosteric receptorsites.
    D) Enzymes are carbohydrates that function as agents that change the rate of reaction without being consumed in the reaction.
    E) Each type of enzyme has a unique shaped active site that gives it specificity.
    Answer: D
  2. Which of the following is part of the first law of

    A) Kinetic energy is stored energy that results from the specific arrangement of matter.
    B) The entropy of the universe is decreasing.
    C) The entropy of the universe is constant.
    D) Energy cannot be transferred or transformed.
    E) Energy cannot be created or destroyed.
    Answer: E
  3. Which of the following would decrease the entropy within a system?
    A) condensation reaction
    B) hydrolysis
    C) catabolism
    D) digestion
    E) respiration
    Answer: A
  4. According to the induced fit hypothesis of enzyme function, which of the following is CORRECT?
    A) A competitive inhibitor can outcompete the substrate for the active site.
    B) The active site creates a microenvironment ideal for the reaction.
    C) The binding of the substrate changes the shape of the enzyme slightly.
    D) Some enzymes become denatured when activators bind to the substrate.
    E) The binding of the substrate depends on the shape of the active site.
    Answer: C
  5. Which term most precisely describes the general process of breaking down large molecules into smaller ones?
    A) catabolism
    B) dehydration
    C) anabolism
    D) metabolism
    E) catalysis
    Answer: A
  6. According to the first law of thermodynamics..
    A) all processes increase the entropy of the universe.
    B) energy is neither created nor destroyed.
    C) the universe loses energy becasue of friction.
    D) matter can be neither created nor destroyed.
    E) systems rich in energy are intrinsically unstable
    Answer: B
  7. The chemical reaction that results in a positive change in "G" is correctly described as?
    A) exergonic
    B) spontaneous
    C) endergonic
    D) exothermic
    E) enthalpic
    Answer: C
  8. How does an enzyme catalyze a reaction?
    A) By changing the equilibrium of a spontaneous reaction.
    B) By supplying the energy to speed up a reaction.
    C) By lowering the energy of activation of a reaction.
    D) By increasing the amount of free energy of a reaction.
    E) By lowering the "delta" G of the reaction.
    Answer: C
  9. Which of these statements regarding enzymes is FALSE?
    A) The activity of enzymes can be regulated by factors in their immediate environment.
    B) Enzymes provide activation energy for the reactions they catalyze.
    C) An enzyme may be used many times over for a specific reaction.
    D) Enzymes display specificity for certain molecules to which they attach.
    E) Enzymes are proteins that function as catalysts.
    Answer: B
Card Set
Introduction to Metabolism
Multiple Choice