regulation of metabolism

Question 1

enzymes

Answer 1

class of protein;
reduce the amt of activation energy;
provide a surface where reactions take place – active site

Question 2

enzyme-substrate complex

Answer 2

forms when a substrate molecule collides w/ active site of its enzyme

Question 3

competitive inhibitors

Answer 3

inhibitory molecule binds to the ACTIVE SITE;

BLOCKS substrate from binding

Question 4

non-competitive inhibitors

Answer 4

molecule that attaches at an allosteric site;(different site from AS)
distorts the shape of active site- causing failure of enzymatic function

Question 5

feedback inhibition

Answer 5

pos (activator) or neg (inhibitor) modulator;

inhibits enzymatic pathway by excess quantities of an end-product of the pathway

Question 6

transcriptional control

Answer 6

expression;
control is at the level of transcription, synthesis of mRNA encoding the enzymes;
Lac operon

Question 7

lac operon regulation

Answer 7

turned on ONLY when glucose is absent & lactose is present;
lactose binds to the lac repressor–>conformational change–>lac repressor falls off DNA–>allows RNA p to transcribe lac operon genes

Question 8

metabolism regulation

Answer 8

cells use energy to synthesize substances in the amounts needs & shut off synthesis before wasteful excesses are produced