what do enzymes do
how
function as catalysts that increase rate of reaction
by lowering the activation energy
are enzymes consumed in the reaction process
NO
enzymes act on the __ in the reaction process
substrate
what is the measure of affinity that an enzyme has towards the substrate
relate it to affinity
KM
amount of substrate required to reach 1/2 vmax
increase km, decrease affinity
decrease km, increase affinity
what is the max velocity of the enzyme in the reaction process
VMAX
what is the relationship between KM and VMAX
KM = 1/2 VMAX
km = x axis vmax= y axis
vmax - maximal velocity of an enzyme catalyzed reaction
km - amount of substrate required to reach 1/2 vmax
what 3 things affect the reaction velocity of an enzyme
substrate concentration
temperature
pH
what are competitive inhibitors
competitive inhibitors - binds to substrate binding site of enzyme
increase KM (lower affinity) no change in Vmax
what are non competitive inhibitors
non competitive inhibitors - binds to site other than substrate binding site
no change in KM (no change in affinity) decrease Vmax (take longer to reach full velocity)
what can you do to competitive inhibitors to abolish its effects
add more substrate to dilute out the inhibitor
what are allosteric enzymes
enzymes that act as rate limiting steps for metabolic processes
phosphofructokinase is allosterically inhibited by what
increase ATP
what is the measure of the amount of energy available to determine if reaction is energetically feasible
gibbs free energy
what is a positive gibbs free energy mean
reaction is unfavorable or not spontaneous
endergonic
what is a negative gibbs free energy mean
reaction is favorable or spontaneous
exergonic
what is a = gibbs free energy mean
equillibrium