2.  Enzymes are Proteins o Made at ribosome o Monomer: AA o Peptide bonds

3. Enzymes act as catalysts o Speed up rxns by lowering activation energy o Activation energy = starting energy

4. Enzymes are reusable - do not get used up Enzymes do not change Enzymes end in –ase EX: Lactase

5. Substrates bind to enzymes at the active site o Substrate – what the enzyme acts on o Active site – where the substrate binds/attaches to

6. 2 ways enzyme and substrate bind 1. Lock & Key – fit perfectly together

7. 2. Induced Fit – enzyme changes shape to fit the substrate

8. Inhibitor (2 types) 1. Competitive – blocks substrate 2. Non-competitive – changes enzyme shape by binding elsewhere

9. Factors affecting inhibitor activity o Denature – decreases function by pH or, temperature or NOT AT OPTIMUM o Substrate [ ] – once enzymes are saturated, activity does not increase o Enzyme [ ] – when enzymes are increased to act on substrates

10. Questions 1. What are enzymes? 2. How do enzymes affect rate of reaction? 3. How does a catalyst speed up a reaction? 4. What is polymerase? 5. Can an enzyme be reused? 6. What would happen to a reaction if the enzyme is removed? 7. If an inhibitor binds to an enzyme on the active site, what type of inhibitor is it? 8. If the substrate binds to the enzyme perfectly at the active site, what type of bond is it? 9. If an inhibitor binds to an enzyme on a different site, what type of inhibitor is it? 10. If the enzyme has to change its shape to fit the substrate, what type of bond is it? 11. If substrate [ ] is saturated, can the enzyme activity increase? 12. If substrate [ ] is saturated, what needs to be added in order for enzyme activity to increase? 13. If enzyme [ ] is saturated, what needs to be added in order for the activity to increase?