Enzymes models of action

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2

5- 40oC

Increase in Activity

<5oC - inactive

Slide 16

Effect of heat on enzyme activty

If you heat the protein above its optimal temperature

bonds break

meaning the protein loses it secondary and tertiary structure

Slide 17

Effect of heat on enzyme activty

Denaturing the protein

Slide 18

Effect of heat on enzyme activty

Denaturing the protein

ACTIVE SITE CHANGES SHAPE

SO SUBSTRATE NO LONGER FITS

Even if temperature lowered – enzyme can’t regain its correct shape

Slide 19

pH

Rate of Reaction

Slide 20

Rate of Reaction

pH

1

3

4

2

5

6

7

8

9

Slide 21

Rate of Reaction

pH

1

3

4

2

5

6

7

8

9

Narrow pH optima

Slide 22

Rate of Reaction

pH

1

3

4

2

5

6

7

8

9

Narrow pH optima

WHY?

Slide 23

Rate of Reaction

pH

1

3

4

2

5

6

7

8

9

Narrow pH optima

Disrupt Ionic bonds - Structure

Effect charged residues at active

site

Slide 24

Enzyme Concentration

Rate of Reaction

Slide 25

Rate of Reaction

Enzyme Concentration

Enzyme Concentration

Slide 26

Substrate Concentration

Rate of Reaction

Slide 27

Rate of Reaction

Substrate Concentration

Substrate Concentration

Slide 28

Rate of Reaction

Substrate Concentration

Substrate Concentration

Active sites full- maximum turnover