Enzymes All chemical reactions convert reactants to products. All chemical reactions convert reactants to products. Ex. 2 HCl + Mg  MgCl 2 + H 2 Ex. 2 HCl + Mg  MgCl 2 + H 2 Enzymes are a class of protein. Enzymes are a class of protein. The job of an enzyme is to catalyze a reaction (help it get started). The job of an enzyme is to catalyze a reaction (help it get started).

Enzymes lower the amount of energy needed to get the reaction going – activation energy. Enzymes lower the amount of energy needed to get the reaction going – activation energy.

Examples DNA polymerase – makes DNA DNA polymerase – makes DNA Rennin – curdles milk protein Rennin – curdles milk protein Lipase – breaks down fats Lipase – breaks down fats Protease – breaks down proteins Protease – breaks down proteins Usually end with “-ase” Usually end with “-ase”

How do enzymes work? The material that an enzyme works on is called a substrate. The material that an enzyme works on is called a substrate. Enzymes work like a lock and key – must have right enzyme for each substrate. Enzymes work like a lock and key – must have right enzyme for each substrate.

How do enzymes work? The active site on the enzyme is what binds to the substrate. Why enzymes? The active site on the enzyme is what binds to the substrate. Why enzymes?Why enzymes?Why enzymes? Specificness and Reusing enzymes

Enzyme Shape The shape of each protein is determined by the sequence of amino acids used to make that protein. The shape of each protein is determined by the sequence of amino acids used to make that protein. Just as for proteins, shape is extremely important. Just as for proteins, shape is extremely important. If proteins/enzymes don’t have the correct temperature, pH, or salt concentration, they will lose their shape or denature and not be able to function. If proteins/enzymes don’t have the correct temperature, pH, or salt concentration, they will lose their shape or denature and not be able to function.Denaturing

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Competitive Inhibition In a process called competitive inhibition, molecules that fit the active site can prevent the enzyme from working. In a process called competitive inhibition, molecules that fit the active site can prevent the enzyme from working.