1. enzymes

2. Enzymes are Proteins Many of our genes code directly for enzymes Estimated to be about 75,000 different types in the human body

3. Enzymes Do…. Do Not… Speed up chemical reactions Allow reactions to occur with less energy input Provide energy for the reaction End up altered or used up or in the product Change the net effect of the reaction (the products are the same with or without an enzyme)

4. So What Do Enzymes Do? They allow bonds to be broken at lower temperatures Thus they lower the activation energy So reactions can happen more easily with less input of energy (at lower temps) *this is why we are not on fire!

5. Enzyme Terminology Substrate = reactant Active site = place on enzyme where the substrate can bind

6. Enzymes are Specific! Only substrates that “match” the active site can be catalyzed Like a lock and key

7. How Do They Do it!?!?!? They may arrange the molecules to make it easier for bonds to break or collisions to happen They may change the environment (make it acidic etc.) May temporarily bond with substrate, stabilize the intermediates etc.

8. http://www.youtube.co m/watch?v=XTUm-75- PL4 http://www.youtube.co m/watch?v=XTUm-75- PL4