Unit 4EnzymesSlide 3Activation EnergyCofactorEnzymatic ReactionsSlide 7Lock-and-Key ModelSlide 9DenaturationEffects of Temperature on Enzymatic ActivityEffects of pH on Enzymatic ActivitySlide 131Unit 4EnzymesEnzymesEnzymes are Catalysts (substances that promote chemical reactions)- Most are proteins (large molecules made up of amino acids) - The sequence and arrangement of these amino acids results in proteins of different sizes and shapes.- Lower the Activation Energy (energy required for a chemical reaction to proceed)2EnzymesSubstrate(s): molecules that are used (consumed) in the reactionProduct(s): molecules that are made in the reaction (what the substrate(s) change into). Enzyme: molecule that causes the change in the substate(s) into the product(s) by Lowering the Activation Energy.- Contains the Active Site: site where substrate binds with enzyme- Is NOT consumed in the reaction3Activation Energy4CofactorCofactor: non-protein molecule that is required for a reaction to occur, but is not an enzyme- NOT consumed in the reaction, either- Required: If not present, the reaction will not occur5Enzymatic ReactionsSubstrate(s) + Enzyme + Cofactor = Product(s) + Enzyme + CofactorNote: the only molecule that changes is the substate(s)67Lock-and-Key Model- Enzyme specificity (specific enzyme for a specific reaction)- Enzyme is the Lock-Substrate is the Key8Lock-and-Key Model- Maintaining structure of the enzyme is critical to its function. - Denaturation: Change in the 3D structure of the enzyme (NO REACTION)9Denaturation1) Too High Temperature2) Too High or Too Low pH3) Heavy MetalNote1: Too Low Temperature or does NOT cause denaturation. Slower reaction, but not a change in the 3D structure of the enzymeNote2: Removal of cofactor does NOT cause denaturation. NO REACTION, but not a change in the 3D structure of the enzyme.1011Effects of Temperature on Enzymatic ActivityEffects of pH on Enzymatic