2. Enzymes Honors Biology

3. Chemical Reactions and Enzymes chemical reaction:

4. Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products)

5. Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy

6. Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy Reactants

7. Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy ReactantsProducts

8. Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen

9. Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen Reactants

10. Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen ReactantsProducts

11. Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen ReactantsProducts chemical equation: CO 2 + H 2 O  C 6 H 12 O 6 + O 2

12. Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen ReactantsProducts chemical equation: CO 2 + H 2 O  C 6 H 12 O 6 + O 2 Reactants

13. Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen ReactantsProducts chemical equation: CO 2 + H 2 O  C 6 H 12 O 6 + O 2 Reactants Products

14. Chemical Reactions and Enzymes II. The speed of a reaction depends on whether it releases or absorbs energy. Reactants Products Activation energy Activation energy Reactants Energy Absorbing Energy Releasing

15. Chemical Reactions and Enzymes A.All reactions require some energy to start: activation energy.

16. Chemical Reactions and Enzymes A.All reactions require some energy to start: activation energy. B.catalyst: substance that speeds up a chemical reaction by lowering the activation energy

17. Chemical Reactions and Enzymes A.All reactions require some energy to start: activation energy. B.catalyst: substance that speeds up a chemical reaction by lowering the activation energy Catalysts found in living things are called enzymes Enzymes are made of Proteins

18. Chemical Reactions and Enzymes C. Enzymes provide a site where the reactants of a chemical reaction can be brought together

19. Chemical Reactions and Enzymes C. Enzymes provide a site where the reactants of a chemical reaction can be brought together are not used up or changed during the chemical reaction

20. Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick)

21. Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick) reactants: called substrate when they stick to the enzyme

22. Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick) reactants: called substrate when they stick to the enzyme substrate only fits into the active site of the correct enzyme (like a key and lock)

23. Labeled diagram: Enzyme Active Site Reactants

24. Enzyme Active Site Reactants III. How does an enzyme work? A. reactant binds to the enzyme Reactant stuck to Active Site

25. Enzyme Active Site III. How does an enzyme work? A. Reactant binds to the enzyme Reactant stuck to Active Site

26. Enzyme Active Site III. How does an enzyme work? B. reactants converted to product Product

27. Enzyme Active Site III. How does an enzyme work? C. products are released – enzyme is free to bind new reactant Product

28. IV. Enzymes only work in specific conditions A. temperature: destroys the shape of the enzyme (protein) B. pH: changes the shape of the enzyme and its active site

29. Enzyme Active Site Temperature or pH Change: Product No Product Made

30. IV. Enzymes only work in specific conditions C. inhibitor molecules: block reactant from entering active site

31. Enzyme Active Site Inhibitor Molecules: Product No Product Made

32. IV. Enzymes only work in specific conditions D. coenzymes: make enzymes work better

33. Enzyme Active Site Enzyme: Peroxidase in liver cells Reactants: Hydrogen peroxide Reactants Hydrogen Peroxide

34. Enzyme Active Site Enzyme: Peroxidase in liver cells Reactants: Hydrogen peroxide Reactants

35. Enzyme Active Site Enzyme: Peroxidase in liver cells Products: Water and Oxygen Product O2O2 H2OH2O

36. Enzyme Active Site Product Enzyme: Peroxidase in liver cells Products: Water and Oxygen More Hydrogen Peroxide O2O2 H2OH2O

37. Substrate Concentration The reaction rate increases until the enzymes become saturated with substrate, and a maximum rate is reached