Enzymes models of action

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1

Slide 1

Enzyme Action

Learning objective: to describe different models for

enzyme action and to investigate factors which control the

rate of an enzyme reaction

18th October

Slide 2

Lock and Key

Slide 3

Lock and Key

However certain substances can bind to the enzyme at sites other than the

Active site and modify its activity (inhibitors/co-factors)

Idea that the enzyme is flexible

Slide 4

Induced Fit

Slide 5

Enzyme reactions

enzyme + substrate

enzyme-substrate complex

Slide 6

Enzyme reactions

enzyme + substrate

enzyme-substrate complex

E +S

ES

Slide 7

Enzyme reactions

enzyme + product

enzyme-substrate complex

E +P

ES

enzyme + substrate

enzyme-substrate complex

E +S

ES

Slide 8

Enzyme activity

How fast an enzyme is working

Rate of Reaction

Slide 9

Enzyme activity

How fast an enzyme is working

Rate of Reaction

Rate of Reaction = Amount of substrate changed (or amount product formed)

in a given period of time.

Slide 10

Rate of Reaction

Enzyme activity

Variable you are looking at

Slide 11

Enzyme activity

Four Variables

Slide 12

Enzyme activity

Four Variables

Temperature

pH

Enzyme Concentration

Substrate Concentration

Slide 13

Temperature

Rate of Reaction

Slide 14

Rate of Reaction

Temperature

0

20

30

50

10

40

60

Slide 15

Rate of Reaction

Temperature

0

20

30

50

10

40

60

40oC - denatures