Chapter 4: Enzymes Flashcards
speed up the rates of reactions by many millions of times without the need for an increase in temperature
enzymes
the biochemical modification and use of organix molecules and energy to support the activities of life
metabolism
even when a reaction is spontaneous the reaction will not start unless a small amount of ___ is added
activation energy
a chemical agent that accelerates the rate of a reaction without being changed by the reaction
catalyst
the reactant that an enzyme acts on is called ?
substrate
each type of enzyme catalyzes the reaction of a single type of substrate molecule or group of closely related molecules
Enzyme Specificity
substrate interacts with a small pocket or groove in the enzyme molecule
active site
further increases in substrate concentration have no effect on reaction rate
saturated
a nonprotein group that binds to the enzyme, for catalytic activity
cofactor
other cofactors are small organic molecules which are often derived from vitamins
-bind loosely to enzymes
coenzymes
inhibitors bind to the active site, blocking access for the normal substrate- sowing or stopping the reaction
competitive inhibition
inhibitors bind at a location other than the active site- reducing the ability of the active to bind substrate
noncompetitive inhibition
enzyme activity is controlled by the reversible binding of a regulatory molecule to the allosteric site
allosteric regulation
a location on teh enzyme outside the active site
allosteric site
excess accumulation of a product often inhibits the enzymatic reaction producing it
feedback inhibition or end- product inhibition
