Enzyme Regulation 1

Competitive Inhibition 2

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

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)

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

Allosteric Regulation http://julieteaslickby411.blogspot.com/2011/04/innervation-of-penis-and-structure-of.html

Allosteric Regulation 7

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

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

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 http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter8/animations.html# 10