Download ENZYME Test REVIEW Answers

ENZYME T e s t REVIEW Answers
1.
An enzyme and four different molecules are shown in the diagram below.
The enzyme would most likely
affect reactions involving
a) molecule A, only
b) molecule C, only
c) molecules B and D
d) molecules A and C
3.
Base your answers to the following questions on the graph below and on your knowledge of
biology.
6. What is the optimal pH for pepsin?
3
7. Is this pH acid or basic?
9. What is the optimal pH for trypsin? 8.5
11. Is this pH acid or basic
12. Neither enzyme works at a pHs of__5_
13. An incomplete graph is shown below. What
two internal body conditions could appropriately
be used to replace letter Z on the axis?
pH or temperature
14. What kind of organic molecule is an enzyme?
protein
15. List 3 environmental factors that affect how well enzymes function. Give details on how each
one affects the rate of enzyme reaction
pH- extremes denature/ change enzyme shape, so they rate decreases
temp –extreme heat denature/ change enzyme shape, so they rate decreases
substrate concentration- as substrate levels decrease, enzyme activity decreases
18. What specific change happens to an enzyme that stops it from working when you heat it?
denature/ change enzyme shape, so they rate decreases
19. Explain why changing the shape of an enzyme could affect the ability of the enzyme to
function
If the shape changes, it will no longer be able to bind to substrate, therefore rendering it inactive
20. Draw a generalized graph of the action of an enzyme from the human body as the
temperature changes from 0°C to 100°C. Mark the temperature of optimal enzyme activity
21. Explain the difference between a competitive and a non-competitive inhibitor
A noncompetitive inhibitor is a substance that interacts with the enyzme, but usually not at the active site.
The noncompetitive inhibitor reacts either remote from or very close to the active site. The net effect of a
non competitive inhibitor is to change the shape of the enzyme and thus the active site, so that the
substrate can no longer interact with the enzyme to give a reaction.
A competitive inhibitor is any compound which closely resembles the chemical structure and molecular
geometry of the substrate. The inhibitor competes for the same active site as the substrate molecule. The
inhibitor may interact with the enzyme at the active site, but no reaction takes place. The inhibitor is
"stuck" on the enzyme and prevents any substrate molecules from reacting with the enzyme.
22. Allosteric enzyme is a type of non-competitive inhibitor