1. ENZYMES
Nature’s Catalysts

2. Enzymes
Proteins that act as biological catalysts to speed up chemical reactions

3. two or more substances combine to form one new substance
SYNTHESIS
two or more substances combine to form one new substance

4. SYNTHESIS
A + B  AB
Na + Cl2  NaCl
Pb(IV) + O2 
Pb2O4

5. when a substance breaks up into simpler substances
DECOMPOSITION
when a substance breaks up into simpler substances

6. Decomposition
AB  A + B
NaCl  Na + Cl2
Pb2O4 
Pb + O2

7. General Formula for Reactions
A + B  C Reactants yields Products

8. Enzymes Identify many enzymes by the suffix –ase:
helicase (unzips DNA)
lactase (breaks down lactose)
peptidyl transferase (forms peptide bonds in polypeptides)

9. Enzymes
speed up biochemical reactions by lowering the activation energy of reactions that would normally happen anyway.

10. The material that the enzyme works on.
Substrates
The material that the enzyme works on.

11. The special fold in the enzyme where the reaction happens
Active Sites
The special fold in the enzyme where the reaction happens

12. Competitive Inhibition
When something besides the substrate blocks the active site

13. Competitive Inhibition
Inhibitors—reduce the productivity of enzymes as seen to the right with herbicides.
The body uses enzymes to control metabolic pathways.

14. Non-Competitive Inhibition
When a molecule binds to another spot on the enzyme causing it to change shape and become inactive

15. Enzymes
Enzymes bind substrates (enzyme reactant) into active sites (pocket or groove on enzyme).
While the enzyme and the substrate are joined, the enzyme catalyzes the reaction and converts the substrate to the product(s).

16. Enzymes
The most classic example an enzymatic reaction is the hydrolysis of sucrose (table sugar) into glucose and fructose.

17. Enzymes
Another look…

18. Factors Afecting Enzyme Activity
Temperature pH
Enzyme Concentration
Substrate Concentration

19. Effects on Enzyme Activity
Rate of Enzyme Activity is influenced by:
Substrate concentration (more substrate = more activity until saturation)
Temperature (higher temperature = more activity until the enzyme’s protein denatures)

20. Effects on Enzyme Activity
Rate of Enzyme Activity is influenced by:
pH (usually in range of 6-8 for humans)
Inhibitors (reduce activity by binding or changing shape of active sites)
Alkaline Intestine
Acidic Stomach

21. Enzymes: Fun Facts
Enzymes work quickly—about 1000 substrates are taken in and converted every second.