Factors affecting enzyme activity Quiz
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5 questions, one answer each
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1. What is the pH of a solution with [H⁺] = 1.0 × 10⁻⁵ mol dm⁻³?
- A. 1.0
- B. 5.0
- C. -5.0
- D. 9.0
2. A competitive inhibitor reduces the rate of reaction because it...
- A. binds to a site away from the active site
- B. denatures the substrate
- C. binds to the active site, so the substrate cannot
- D. increases the activation energy of the substrate
3. The rate of an enzyme-controlled reaction stops increasing as substrate concentration increases. Why?
- A. The substrate has been denatured
- B. The temperature has fallen
- C. The pH has changed to the optimum
- D. All the active sites are occupied
4. What happens to an enzyme at a temperature well above its optimum?
- A. The ionic and hydrogen bonds in its tertiary structure break, so the active site changes shape
- B. The peptide bonds of the substrate break
- C. The activation energy rises to its highest value
- D. The enzyme becomes complementary to more substrates
5. Which is the best way to keep pH constant in an enzyme investigation?
- A. Use a water bath
- B. Repeat the experiment three times
- C. Use a buffer solution
- D. Use a larger volume of substrate