ENZYMESENZYMES

WHAT DO ENZYMES DO?WHAT DO ENZYMES DO?

The reaction starts with activationThe reaction starts with activation

energy.This activation energy isenergy.This activation energy is

decreased by the enzymes. So we candecreased by the enzymes. So we can

say that enzymes which are biologicalsay that enzymes which are biological

catalysts quicken the reactioncatalysts quicken the reaction by by

decreasing activation energy. decreasing activation energy.

STRUCTURE STRUCTURE OFOF

ENZYMESENZYMES

SİMPLE ENZYMES:SİMPLE ENZYMES:

*They are made up of apoenzymes.*They are made up of apoenzymes.

Apoenzymes:Apoenzymes: * They are made up of * They are made up of

proteins.proteins.

* The diversity of enzymes is * The diversity of enzymes is

provided by this part. provided by this part.

* It knows the substrate, which * It knows the substrate, which

an enzyme acts.an enzyme acts.

COMPLEX ENZYMES:COMPLEX ENZYMES:

Coenzyme : Coenzyme : They are made up of organicThey are made up of organic

molecules. molecules.

Ex : VitaminsEx : Vitamins

Cofactors: Cofactors: They are made up ofThey are made up of

ınorganic molecules.ınorganic molecules.

Ex: MineralsEx: Minerals

*Apoenzymes can work only with one*Apoenzymes can work only with one

coenzyme or cofactor.coenzyme or cofactor.

PROPERTIES PROPERTIES OF OF

ENZYMES:ENZYMES:

1)1) SPECIFICITY:SPECIFICITY: Enzymes are specific Enzymes are specific and work with only one single type ofand work with only one single type of

substrate. substrate.

2) 2) REVERSIBILITY :REVERSIBILITY : The same enzyme The same enzyme works for the forward and reverse of the works for the forward and reverse of the reactıon. Except digestive enzymes. reactıon. Except digestive enzymes.

3) 3) NAMING :NAMING : Enzymes are named Enzymes are named accordıng to the molecules on whıch accordıng to the molecules on whıch they act, or accordıng to the type of they act, or accordıng to the type of reaction that they catalyze.reaction that they catalyze.

4) 4) THE EXACT POINT THE EXACT POINT OF EFFECT :OF EFFECT :

The enzymes showThe enzymes show

their effect on thetheir effect on the

surface of the subtrate.surface of the subtrate.

So this meansSo this means

that the wider thethat the wider the

surface area of thesurface area of the

substrate, the greatersubstrate, the greater

the rate of the reactıon. the rate of the reactıon.

5) 5) SPEED : SPEED : Enzymes speed up the Enzymes speed up the reactions.They speed up the reactıons by reactions.They speed up the reactıons by decreasing the activation energy. decreasing the activation energy.

6) WORK IN TEAMS :6) WORK IN TEAMS : The enzymesThe enzymes

work as teams. The product of onework as teams. The product of one

reactıon catalyzed by an enzyme canreactıon catalyzed by an enzyme can

be the substrate for another enzyme.be the substrate for another enzyme.

7) PLACE OF SYNTHESIS: 7) PLACE OF SYNTHESIS: The apoenzyme The apoenzyme part of the enzymes is synthesized in the part of the enzymes is synthesized in the ribosomes just like every protein. If the gene is ribosomes just like every protein. If the gene is responsible for the synthesis of one specific responsible for the synthesis of one specific enzyme is destroyed, than the cell won’t be enzyme is destroyed, than the cell won’t be able to conduct that reaction and this situation able to conduct that reaction and this situation can even be lead to the death of the cell.can even be lead to the death of the cell.

QUESTIONS:QUESTIONS:

LET’ ANSWER THEM LET’ ANSWER THEM

1)True or false:1)True or false:

(……….) Enzymes quicken the reactions(……….) Enzymes quicken the reactions(……….) Apoenzymes are proteins.(……….) Apoenzymes are proteins.(……….) All enzymes are reversibl.(……….) All enzymes are reversibl.(……….) Coenzymes are minerals.(……….) Coenzymes are minerals.(……….) Apoenzymes know the substrate.(……….) Apoenzymes know the substrate.(……….) Specifity is the not the property of (……….) Specifity is the not the property of enzymes enzymes (……….) The enzymes work as teams.(……….) The enzymes work as teams.

2) 2) The best description of an enzyme is The best description of an enzyme is that ;that ;

A)A) Becomes hydrolyzed during chemical Becomes hydrolyzed during chemical synthesissynthesis

B)B) Becomes dehydrated during chemical Becomes dehydrated during chemical synthesissynthesis

C) Speeds up the rate of chemical reactions C) Speeds up the rate of chemical reactions

D) Serves as an inorganic catalystD) Serves as an inorganic catalyst

E) Starts biochemical E) Starts biochemical

3)What is the difference between a3)What is the difference between acofactor and a coenzyme?cofactor and a coenzyme?

A)A) Coenzymes are proteins; cofactors are notCoenzymes are proteins; cofactors are notB)B) Coenzymes are not proteins; cofactors are Coenzymes are not proteins; cofactors are

protein in natureprotein in natureC)C) Coenzymes are organic molecules; cofactors are Coenzymes are organic molecules; cofactors are

generally inorganicgenerally inorganicD)D) Coenzymes are organic molecules; cofactors are Coenzymes are organic molecules; cofactors are

notnotE)E) Coenzymes activate enzymes; cofactors activate Coenzymes activate enzymes; cofactors activate

coenzymescoenzymes

4) 4) Which statement about enzymes is wrong?Which statement about enzymes is wrong?

A)A) Some enzymes can function outside the organismSome enzymes can function outside the organism

B)B) Digestive enzymes are reversibl.Digestive enzymes are reversibl.

C)C) Enzymes are used many times over and over againEnzymes are used many times over and over again

D)D) An enzyme can affect only one kind of substrateAn enzyme can affect only one kind of substrate

E)E) Enzymes are destroyed at high temperaturesEnzymes are destroyed at high temperatures

TTHHAANNKKSS