1. MARY MCGINTY, KELSEY LORENZ MCKENZIE MERRICK, ANGELINA LIDDY Feedback Inhibition

2. Definition A metabolic pathway is switched off by the inhibitory binding of its end product to an enzyme that acts early in the pathway. http://youtu.be/Ph_ZCnW _N_o http://youtu.be/Ph_ZCnW _N_o http://highered.mcgraw- hill.com/olcweb/cgi/plugin pop.cgi?it=swf::535::535::/ sites/dl/free/0072437316/ 120070/bio10.swf::Feedba ck%20Inhibition%20of%2 0Biochemical%20Pathways http://highered.mcgraw- hill.com/olcweb/cgi/plugin pop.cgi?it=swf::535::535::/ sites/dl/free/0072437316/ 120070/bio10.swf::Feedba ck%20Inhibition%20of%2 0Biochemical%20Pathways

3. Characteristics Prevents the cell from wasting chemical resources b/c shuts reaction down Different parts of an enzyme are bonded to by the stopper-changes shape so enzyme is no longer active Repeats: stopper leaves & can be reused

4. Example Respiration:  Maintains homeostasis in body  Converts glucose to CO2 and water, forming ATP in the process  When cell has low concentration of ATP(energy), the citric acid cycle feeds the electron transport chain, thus producing ATP  As ATP builds up, citric acid cycle shuts down b/c citric acid is no longer being produced due to citrate synthase

5. Clinical Case General hormones  When hormone levels are higher than the set point, feedback inhibitors stop the input into the enzyme so that no more is produced  Hormones are used up—feedback inhibitors re-allow input to the enzyme –creates more to reach set point

6. Videos http://youtu.be/Ph_ZCnW_N_o http://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535: :/sites/dl/free/0072437316/120070/bio10.swf::Feed back%20Inhibition%20of%20Biochemical%20Path ways http://highered.mcgraw- hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535: :/sites/dl/free/0072437316/120070/bio10.swf::Feed back%20Inhibition%20of%20Biochemical%20Path ways