Enzymes:

“The Molecules of Life”

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EnzymesEnzymes•Are proteins•Are specific

for what they will catalyzecatalyze

•Are ReusableReusable•End in –asease

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How do enzymes Work?How do enzymes Work?

Enzymes work by weakening weakening bondsbonds which which lowers lowers activation activation energyenergy

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EnzymesEnzymes

FreeEnergy

Progress of the reaction

Reactants

Products

Free energy of activationFree energy of activation

Without Enzyme

With Enzyme

______________ to get a chemical reaction _______________

= ________________________

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ACTIVATION ENERGY

REACTANTSPRODUCTS

ACTIVATIONENERGY

Energy requiredSTARTED

___________ HELP CHEMICAL REACTIONS _______________

Catalysts work by ____________ the___________________________to get a chemical reaction started.

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DECREASING

CATALYSTS

ACTIVATION ENERGY required

HAPPEN FASTER

PROTEINS CAN BE ENZYMES

SUBSTRATE

ENZYME-SUBSTRATE COMPLEX

PRODUCTSENZYMEUnchanged& Reusable

ENZYME

Image modified from: http://www.biologie.uni-hamburg.de/b-online/library/cat-removed/enzyme_.gifArrow: http://www.gifanimations.com/action/ImageDisplay/1/2/11/next

ACTIVESITE

SubstrateSubstrate

• The substancesubstance (reactant) an enzymeenzyme acts on.

Enzyme

Substrate

Active SiteActive Site

• A restricted regionrestricted region of an enzymeenzyme molecule which bindsbinds to the substratesubstrate.

Enzyme

Active Site

Substrate

Click HERE to learn more about enzymes

ENZYMES _____ like a _______________

to only _________of _________.

Enzymes are ___________ by thereaction and ___________

LOCK AND KEY

REUSABLEUNCHANGED

FIT

ONE KIND SUBSTRATE

http://www.grand-illusions.com/images/articles/toyshop/trick_lock/mainimage.jpg

Lock and Key

FACTORS THAT AFFECT ENZYME ACTIVITY

__________ & ______________

Conditions that are TOO ACIDIC

or TOO HOT cause proteins to________ or _________

pH temperature

UNWIND DENATURE

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See a movieChoose narrated

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Denaturing _______ the _______ of the ______________ so enzyme ______________ to ____________

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_______________ (keeping pH and temperature constant) is ______________ for maintaining ____________________

HOMEOSTASIS

changes shapeACTIVE SITE

CAN’T BIND SUBSTRATE

IMPORTANTENZYME FUNCTION

37°

Temperature

temperature

reacti

on

rate

What’s happening here?!

Concept Check:

Label the following on the diagram below:

enzyme, active site, substrate

For enzymes…What matters?

SHAPE!