The Return of Enzymes



So I’m back again with another quiz, this time based on enzymes. However this quiz is a little different from the ordinary multiple choice quizzes you usually see. Don’t panic! Its fairly simple and I’m sure you will all get the hang of the answer key pretty quickly. Again, it’s just for you to review the topic, so have fun! 😀

For questions 1-10, choose the correct multiple answer using ONE of the keys A, B, C, D or E as follows:

A. 1, 2 and 3 are correct

B. 1 and 3 are correct

C. 2 and 4 are correct

D. Only 4 is correct

E. All are correct

1)      What is an enzyme?

  1. A biological catalyst
  2. Speeds up chemical reaction
  3. Provides an alternative pathway with a lower activation energy
  4. The primary sequence of amino acids

2)      What is the definition of the activation energy?

  1. All  energy used to convert the substrates to products
  2. The free energy for the reaction
  3. The highest energy needed for the reaction to occur
  4. The minimum amount of energy needed for the reaction to occur

3)      The turnover number is

  1. Represented by “kcat
  2. The number of molecules of product converted to substrate per enzyme molecule per second.
  3. The number of molecules of substrate converted to product per enzyme molecule per second.
  4. The amount of amino acid residues per turn in the α-helix

4)      Which of the following is/are correct?

  1. Co-factor:  active enzyme
  2. Apoenzyme: inactive protein part
  3. Holoenzyme : inactive protein part
  4. Co-facto: non-protein part

5)      Which of the following is/are a class of enzyme?

  1. Transferases
  2. Hydrolases
  3. Ligases
  4. Nucleases

6)      The interactions between the active site and the substrate occur via which of the following forces?

  1. Hydrogen bonding
  2. Covalent bonding
  3. Van Der Waals interactions
  4. Metallic bonding

7)      Which of the following describes enzyme specificity as being “too rigid”?

  1. The Non-Productive Binding Model
  2. Strain and Distortion
  3. Koshland’s Induced Fit Hypothesis
  4. Fischer’s Lock and Key Hypothesis

8)      Which of the following affect reaction velocity?

  1. Substrate concentration
  2. Enzyme concentration
  3. pH
  4. Pressure

9)      Which of the following is/are types of reversible inhibition?

  1. Conformational Inhibition
  2. Competitive Inhibition
  3. Irreversible Inhibition
  4. Mixed Inhibition

10)   In Noncompetitive Inhibition:

  1. Vmax is decreased
  2. Vmax remains the same
  3. Km is unchanged
  4. Km is increased