Do Now Do Now Answers N C L

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Do Now Answers N C L L C N C A P P

Enzymes Proteins that catalyzes a chemical reaction

• What happens to the food we eat? It breaks down into…. • Carbohydrates • Lipids • Proteins

What are Enzymes? • Enzymes are proteins • Enzymes act as a catalyst to speed up a chemical reaction

Chemical Reaction: Reactants form Products

Let’s Look at Lactose…. • What is lactose? • Lactose is a disaccharide found in dairy products

What is lactose-Intolerance? • They lack the enzyme: LACTASE • Sugars end in “-ose” • Enzymes end in “-ase”

Enzymes Characteristics • Are specific for what the enzyme will catalyze • Are Reusable • End in –ase • Named for the reaction they help: • Sucrase breaks down sucrose • Proteases breakdown proteins • Lipases breakdown lipids • DNA polymerase builds DNA

Enzymes can be reused again and again Substrate (Reactant) Product Active Site Enzyme-Substrate Complex Enzyme

It’s Shape that Matters!!! • Lock & Key Model • Shape of enzyme allows substrate to fit • Specific Enzyme for each specific reaction

How do enzymes work? • Enzymes work by weakening bonds which lowers activation energy Reactions can occur without the help of catalysts, but not at the speed our body requires. “The energy needed to start a reaction”

Activation Energy • The energy needed to start a reaction. • For example a car needs a car battery to start. It is like a discount on the cost of the reaction

Activation Energy

What Affects Enzyme Activities • 1. Environment Conditions • p. H, temperature, enzyme or substrate concentration • 2. Cofactors and Coenzymes • Substances needed for the enzyme to work • 3. Enzyme Inhibitors • Bind and block the enzyme form working

Denaturing • Denaturing: extreme temperature and p. H can change enzyme shape, rendering it useless.

Temperature • High temperatures cause enzymes to denature(unfold and lose shape) • Low temperatures slow molecules down and fewer collisions occur between enzymes and substrate.

Enzymes and p. H • Different enzymes work best at different p. H values. • The p. H that makes the enzyme most active is known as the optimum p. H. • If the p. H is very high or very low, enzymes can be denatured.