Enzymes and Catalysts BIOLOGY 20 21 Catalysts Lesson

Enzymes and Catalysts BIOLOGY 20 -21

Catalysts Lesson Objectives By the end of this lesson you should be able to: Relate changes in energy to the rate of a chemical reaction Explain how catalysis affect the energy of a chemical reaction Describe the lock and key mechanism of enzymes in chemical reactions

Words to Know Enzyme: proteins or RNA molecules that function as catalysts in living things Products: elements or compounds that are produced by chemical reaction Activation energy: the energy that is needed to get a reaction started Reactants: elements or compounds that go into a chemical reaction Substrates: reactants that are catalyzed by an enzyme Chemical reaction: a process that changes one or more reactants into one or more products Catalysts: substances that influence a reaction but do not participate in the reaction

Chemical Reactions Chemical reaction: a process that changes one set of chemicals into another set of chemicals Involves breaking bonds and forming new bonds Reactants: the elements or compounds that go into a chemical reaction Products: the elements or compounds that are produced by a chemical reaction

Chemical Reactions and Equations Real world connection A chemical reaction occurs when a candle burns This reaction requires energy This is called activation energy

Types of reactions Exothermic reactions Release energy into the environment Example: exploding fireworks Endothermic reactions Absorb energy from the environment Example: photosynthesis

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Reaction rate The speed at which the reactant change into products Influenced by: The concentration of reactants Temperature Pressure p. H

Catalysis Catalyst: a substance that influences the reaction but do not participate in the reaction Provides alternate pathway for reaction to proceed Changes rate of reaction but not reaction itself Not a reactant or product

Catalysis in living Things Catalyst is a carbon anhydrase Reaction occurs 10 miliion times faster Enzymes proteins that function as catalysis in living things Specific to one biochemical reaction Provide site for reaction to take place

Enzymes at work Substrate: a reactant that is catalyzed by an enzyme One enzyme and one substrate fit together like a lock and key

Lactose intolerance Real world connection Small intestine does not make enough lactose Lactase breaks down lactose, the sugar found in milk People who are lactose intolerant have stomach pain and other uncomfortable symptoms when they eat or drinking dairy products such as milk or cheese.

What effect do enzymes have on biochemical reaction?

Review: Chemical Reactions Reactants Products Require activation energy Exothermic or endothermic Rate can be affected by Concentration of reactants Temperature Catalysts p. H

Review: Catalysts and enzymes Catalysts influence reaction but do not participate in them Enzymes: Are catalysts in living things Bind with substrates through a lock and key mechanism to speed up reactions