ENZYMES 2-4

Chemical reactions need help to get started. Ex: A fire needs a match to get it started.

______________ to get a chemical reaction _______________ = ________________________ Image from: Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved ACTIVATION ENERGY REACTANTS PRODUCTS ACTIVATION ENERGY Energy required STARTED

___________ HELP CHEMICAL REACTIONS _______________ Catalysts work by ____________ the ___________________________to get a chemical reaction started. Image from: Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved DECREASING CATALYSTS ACTIVATION ENERGY required HAPPEN FASTER

IT’S LIKE PUSHING A SNOWBALL UP A HILL Once it gets to top... it can roll back all by itself

CATALYSTS in Living Things In living systems __________ that ________________to control chemical reactions are called = _________ Image from: More about this in Chapters 7,8,9 and 12 PROTEINS act as catalysts ENZYMES

PROTEINS CAN BE ENZYMES SUBSTRATE ENZYME-SUBSTRATE COMPLEX PRODUCTS ENZYME Unchanged & Reusable ENZYME Image modified from: Arrow:

ENZYMES _____ like a _______________ to only _________of _________. Enzymes are ___________ by the reaction and ___________ LOCK AND KEY REUSABLE UNCHANGED FIT ONE KIND SUBSTRATE

FACTORS THAT AFFECT ENZYME ACTIVITY __________ & ______________ Conditions that are TOO ACIDIC or TOO HOT cause proteins to ________ or _________ pH temperature UNWIND DENATURE

Denaturing _______ the _______ of the ______________ so enzyme ______________ to ____________ Image modified from: _______________ (keeping pH and temperature constant) is ______________ for maintaining ____________________ HOMEOSTASIS changesshape ACTIVE SITE CAN’T BIND SUBSTRATE IMPORTANT ENZYME FUNCTION

Many enzyme NAMES end in _____ and the beginning of the name tells what it does DNA Polymerase= “polymerizes” joins monomers to make DNA Protease= breaks down proteins ATP synthase= synthesizes ATP -ASE