Unit 4 Target 1: Enzymes Quiz

11 Questions | Total Attempts: 1022

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Unit 4 Target 1: Enzymes Quiz


Questions and Answers
  • 1. 
    How do enzymes speed up chemical reactions?  
    • A. 

      By reducing activation energy

    • B. 

      By reducing energy produced by the reaction

    • C. 

      By increasing activation energy

    • D. 

      By increasing energy produced by the reaction

  • 2. 
    Pepsin is a protein-digesting enyme in the human stomach. Antacids cause the pH of the stomach to increase and protein digestion becomes less efficient. What occurs to reduce the efficiency of protein digestion?
    • A. 

      Antacids break the covalent bonds within pepsin.

    • B. 

      Pepsin dissolves antacids in the gastric juice.

    • C. 

      The active site of pepsin changes shape.

    • D. 

      The concentration of pepsin increases.

  • 3. 
    Two students conduct an experiment in which they measure the concentration of an enzyme in a test tube at 1 minute intervals over the course of an enzymatic reaction. Each of the students makes a prediction about what will happen to the enzyme concentration as the reaction progresses.Student 1 predicts that the concentration of the enzyme in the test tube will decrease as the reaction progresses.Student 2 predicts that the concentration of the enzyme in the test tube will stay the same as the reaction progresses.The results of the experiment will most likely support the prediction of which student? 
    • A. 

      Student 1; enzymes are depleted as a reaction progresses.

    • B. 

      Student 1; enzymes are not depleted as a reaction progresses.

    • C. 

      Student 2; enzymes are depleted as a reaction progresses.

    • D. 

      Student 2; enzymes are not depleted as a reaction progresses.

  • 4. 
    Without enzymes, the chemical reactions in the body would   
    • A. 

      Happen too fast.

    • B. 

      Occur at much the same rate as they do with enzymes.

    • C. 

      Require a different pH.

    • D. 

      Occur too slowly to support life processes.

  • 5. 
    Which of the following statements about enzymes is NOT true?      
    • A. 

      Enzymes work best at a specified pH.

    • B. 

      All enzymes have the same shape as their substrates.

    • C. 

      Enzymes are proteins.

    • D. 

      The shape of an enzyme allows it to do its job.

  • 6. 
    Which of the following statements is true about catalysts?
    • A. 

      Catalysts slow down the rate of chemical reactions.

    • B. 

      All catalysts are enzymes.

    • C. 

      Catalysts are used up during a chemical reaction.

    • D. 

      Catalysts lower the activation energy of a chemical reaction.

  • 7. 
    Enzymes affect the reactions in living cells by changing the 
    • A. 

      Products of the reaction.

    • B. 

      Speed of the reaction.

    • C. 

      Temperature of the reaction.

    • D. 

      PH of the reaction.

  • 8. 
    The active site of an enzyme is
    • A. 

      Where the reactant fits into the enzyme

    • B. 

      Where the enzymes and molecule bond together

    • C. 

      When the balance of living organisms affects the enzyme

    • D. 

      The same shape in all enzymes

  • 9. 
    What is the term used to describe the energy needed to get a reaction started?
    • A. 

      Adhesion energy

    • B. 

      Activation energy

    • C. 

      Cohesion energy

    • D. 

      Chemical energy

  • 10. 
    A substance that accelerates the rate of a chemical reaction is called a(an) 
    • A. 

      Catalyst.

    • B. 

      Lipid.

    • C. 

      Molecule.

    • D. 

      Element.

  • 11. 
    Refer to the graph above. Reaction 3 in the graph
    • A. 

      Probably occurred in the presence of a catalyst.

    • B. 

      Requires a greater activation energy than reaction 2.

    • C. 

      Is the same as reaction 1, but faster.

    • D. 

      Takes longer than reaction 2.

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