National BiologyProtein and enzymes c: Enzyme

specificity

RecapDraw lolly stick/name/number out of hat to

select one person in class to recap what was talked about/learned in the last lesson

Warning! Be on your guard it may be your turn next!!

What are we learning today?

We are learning to:Give examples of enzyme controlled reactions

to illustrate enzyme specificity

Success criteria:An enzyme is specific to one substrateGive examples

What does enzyme specificity mean?The substance an enzyme acts on is the

SUBSTRATE.What is made in the reaction is called the

PRODUCT.

Experiment 2Aim: to find out what is meant by enzyme

specificity using enzymes and various substrates

A

Amylase and starch test for sugar using clinistix

B

Amylase and hydrogen peroxide test for oxygen using glowing splint

C

Catalase and hydrogen peroxide test for oxygen using glowing splint

D

Catalase and starch test for sugar using clinistix

Experiment conclusionsCatalase only acts on hydrogen

peroxideAmylase only acts on starch

Enzymes are SPECIFICThis means that they only work on one substrate

Enzymes are complimentary in shape to their substrate

Enzymes are SpecificKEYS are SPECIFIC to

LOCKS

ENZYMES are SPECIFIC to SUBSTRATES

water oxygenhydrogenperoxide

cata

lase

Enzymes are SpecificCatalase (enzyme) will only act on hydrogen

peroxide (substrate)

hydrogenperoxide water oxygen

cata

lase

Starch

cata

lase

No reaction No products formed

Enzymes are SpecificOnly catalase will catalyse the breakdown of

hydrogen peroxide

hydrogenperoxide water oxygen

cata

lase

No reaction No products formed

hydrogenperoxide

am

ylase

Enzymes are SpecificRemember:

Enzymes are specific because of their shape.

hydrogenperoxide water oxygen

cata

lase

No reaction No products formed

hydrogenperoxide

am

ylase

The shape of amylase is different to catalase so it will not catalyse the reaction.

The Active SiteWhere a substrate

attaches to an enzyme is called the active site

The active site is where the reaction occurs

The active site is complimentary to the shape of the substrate

The amino acid sequence determines the shape of the active site

bbcbitesize Standard Grade Biology

SummaryExit ticketDraw a diagram (not like one you have seen

today) to show what you understand about enzyme specificity