1. Aim: What can affect the rate of enzyme reactions?

2. What do we mean when we say reaction rate?
How can we speed up
reactions?
Add Enzymes
Another word for reaction rate, is the speed of a reaction.

3. How do enzymes work? A + B AB
Enzymes bind to the substrate so the chemical
reaction can take place.
ENZYME
A + B AB

4. How can we speed up a chemical reaction even more?
Increase enzyme concentration
Increase substrate concentration

5. How can we speed the number of cars that can be built?
Increase workers
Increase car parts
(Enzymes)
(Substrates)

6. Increasing Substrate Concentration:
As substrate
Concentration
increases,
The reaction rate
increases &
then remains
The same
Enzyme
A + B
AB + H2O

7. Increasing enzyme concentration:
As enzyme
Concentration
increases,
The reaction rate
increases &
then remains
The same
Enzyme
A + B
AB + H2O

8. How can we increase the rate of a chemical reaction?
How can we speed up
enzyme activity?

9. So, how do we speed up this chemical reaction?
Enzyme
A + B
AB + H2O

10. *What is the relationship between temperature & enzyme activity in the graph below?
Optimum
As temperature increases, enzyme activity increases up to its optimum & then decreases
*Optimum means the most favorable temperature for the reaction to occur.
*The optimum temperature for this enzyme = 40 0C

11. What is the optimal temperature for most human enzymes?
37 0C

12. What is the range at which this enzyme works?
Between O 0C

13. Why does Enzyme activity begin to decrease after the optimum Temperature?
The enzyme changes shape = DENATURATION

14. So, how much have you learned?
What is the temperature range at which A, B, C work at?
At what range are A & B active at the same time?
What are their optimum temperatures?
At what temperature does B begin to denature?
A=2-37, B=3-98, C=37-120 A B C
3 - 37
A = 4, B = 37, C = 95
B = 38+
*(END OF PAGE 2)*

15. What is PH? -how acidic or basic a substance is….

17. What is the relationship between pH and enzyme activity?
As pH increases from _______ to _________, enzyme activity increases and then decreases
acidic
basic

18. When is enzyme activity at its greatest?
*At its optimum pH.

19. What is the optimal pH for human enzymes?

20. What is the range at which this enzyme works?
Between 1 to 11

21. Why does Enzyme activity begin to decrease after the optimum pH?
DENATURE:
Loses shape

22. Pepsin & Trypsin Enzymes in our body that help hydrolyze
proteins into amino
acids.
hydrolyze
Pepsin- stomach
Trypsin- small intestine

23. pH in stomach is about 2 Are the stomach juices acidic or basic?

24. So, how much have you learned?
What is the pH range at which A & B work at?
At what range are they both active?
What are their optimum pH’s?
Would enzymes A & B be found in the same location in our body? Why?
A = 0 -6, B = 2-9
2 - 6
A = 3, b = 6.5
No. Enzymes are specific based on their shape & conditions.