Enzymes: “ The Molecules of Life” s1

2Enzymes Are proteins catalyzeAre specific for what they will catalyze ReusableAre Reusable aseEnd in –ase

3 How do enzymes Work? weakening bonds which lowers activation energy Enzymes work by weakening bonds which lowers activation energy

4 Enzymes Free Energy Progress of the reaction Reactants Products Free energy of activation Without Enzyme With Enzyme

______________ 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

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

Substrate substance enzymeThe substance (reactant) an enzyme acts on. Enzyme Substrate

Active Site restricted region enzyme binds substrateA restricted region of an enzyme molecule which binds to the substrate. Enzyme Active Site Substrate

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

Lock and Key

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

1 2 3

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

37° Temperature temperature reaction rate What’s happening here?!

Concept Check: Label the following on the diagram below: enzyme, active site, substrate

For enzymes… What matters? SHAPE!