1. 1 Enzymes

2. 2 What Are Enzymes? ProteinsMost enzymes are Proteins catalystspeed up catalyzeEnzymes act as a catalyst to speed up (catalyze) a chemical reaction Enzymes are not permanently changedEnzymes are not permanently changed in the process of a chemical reaction.

3. 3 3 Big Ideas 1.Enzymes are specific for what they catalyze.. 2. Enzymes are reuseable. 3. Enzymes end in - ase - amylase - protease - lipase - lactase

4. 4 How do enzymes Work? lower the amount of energy Enzymes lower the amount of energy the reaction needs. activation energy This energy is called activation energy because is activates the reaction.

5. 5Enzymes Free Energy Progress of the reaction Reactants Products Free energy of activation Without Enzyme With Enzyme

6. 6 Binding to the Enzyme enzyme substrate. The enzyme reacts with the substrate. Enzyme Substrate Joins

7. 7 Binding to the Enzyme active siteThe active site of an enzyme molecule is where the substrate binds to the enzyme. Enzyme Substrate Active Site

8. 8 What Affects Enzyme Activity? Three things:Three things: 1.Environmental Conditions 2.Cofactors and Coenzymes 3.Enzyme Inhibitors

9. 9 1. Environmental Conditions 1. Extreme Temperature are the most dangerous 1. Extreme Temperature are the most dangerous - denature (unfold) enzyme. - high temperature may denature (unfold) the enzyme. 2.pH (most like 6 - 8 pH near neutral) 3.Ions in a solution (like salt)

10. 10 2. Cofactors Cofactors are other molecules that have to attach to the enzyme for it to work.Cofactors are other molecules that have to attach to the enzyme for it to work. Example:Example: Ironenzyme hemoglobin Iron must be present in the enzyme hemoglobin in order for it to pick up oxygen.

11. 11 3. Enzyme Inhibitors Competitive inhibitors compete with the substrate by blocking the active site. Enzyme Competitive inhibitor Substrate

12. 12Inhibitors Noncompetitive inhibitors: bind to another part enzymeforce the active site to close Inhibitors that bind to another part of the enzyme and force the active site to close so that the substrate doesn’t fit. Enzyme active site altered Noncompetitive Inhibitor Substrate

13. 13 Review Questions 1.Which type of biomolecule is an enzyme? 2.What do enzymes do to reactions? 3.What is the name of the thing that binds with the enzyme? 4.What are the three factors that can affect enzyme activity? 5.What are the two types of enzyme inhibitors and how do they work?

14. 14 Cell Organelles Review What does it look like and what does it do? NucleusMitochondriaRibosomes Golgi ApparatusChloroplastsCentrioles LysosomeEndoplasmic Reticulum (smooth and rough) Cell WallCentral VacuoleMembrane ( Nucleolus PlasmodesmataVesicles)

15. 15 Example: Muscle Movement Our muscles move by the interaction of 2 proteins known as actin and myosin. 1.The actin have active sites which bind with the myosin to contract the muscle. 2.The binding sites on the actin are block by tropomyosin, a filament that keeps the actin from reacting with the myosin when we are not using our muscles. 3.Calcium ions bind to the troponin complex on the tropomyosin protein and change its shape. 4.The shape-change causes it to rotate and expose the actin active sites, which then bind with myosin.

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