1. Enzyme Regulation 1

2. Competitive Inhibition2

3. Competitive Inhibition
Competitive inhibitors
have a similar structure to the substrate
competes for the enzyme’s active site and block the substrate from binding
Concentration effect
of inhibitor??? 3

4. Irreversible Inhibitors
Similar to Competitive inhibitors
• exception to destroying the enzyme activity altogether by never letting go or destroying the active site.
Many drugs & pesticides act as irreversible inhibitors of enzymes
•antibiotics (inhibit bacterial enzymes)

5. Allosteric Regulation
some enzymes have allosteric sites
allosteric regulators either inhibit or stimulate an enzyme’s activity 5

6. Allosteric Regulation

7. Allosteric Regulation7

8. Allosteric Regulation
allosteric activators promote the action of the enzyme
allosteric inhibitors prevent the action of the enzyme (i.e. noncompetitive inhibition) 8

9. (Image from: http://classes. midlandstech9

10. Feedback Inhibition
often used to regulate multi-step metabolic pathways
A product of a pathway acts as an allosteric inhibitor of the first enzyme of the pathway 10