Enzymes Flashcards
structure of enzymes
attach to substrates by the active site, active sites are specific, the 3D shape of enzymes allows them to also be specific
are enzymes reactants
no as they are not destroyed or used up during a chemical reaction
function of enzymes
catalysts in chemical reactions, the work by lowering the activation energy required by a cell therefore increasing reaction rate
two ways enzymes can attach to substrates
induced fit model theory, lock and key model theory
induced fit model theory
enzymes alter their shape to fit the substrate, the active site continues to change until the substrate is completeley bound to it, only then will the final shaoe and charge be determined
lock and key model theory
the shape of the substrate exactly matches/is complementary to the active site of the enzymes, no change is necessary from the active site or substrate in order to bind together
when is an enzyme considered denatured
when the active site is altered to the point it can no longer attach to the substrate, therefore a denatured enzyme cannot catalyse a reaction, it cannot be restored to its original shape, denaturation is permanenet
what causes an enzyme to denature
changes in temps and pH’s of the enzymes environment
for enzymes, what affects rate of reaction
temp, pH, concentration of enzymes, concentration of substrates, inhibitors, cofactors and coenzymes
how does concentration of enzymes and substrates affect rate of reaction
more enzymes and more substrates= more collisions so moree reactions, the increase will only continue if there is an enzyme/substrate supply that is endless, if not point of saturation is reached
types of inhibitors
competitive, non-competitive, irreversable, reversible
irreversible inhibitors
bind to enzyme with strong covalent bonds that chhange the protein chemically which cant be reversed
inhibitors
substances that bind to the enzyme and stop it from working to its full capacity
reversible inhibitors
bind non-covalently to enzymes, non covalent bonds are easily broken therefore seperating the inhibitor and enzyme which can then continue catalysing as normal
competitive inhibitors
have a similar shape yo tthe substrate so bind to the active site, making it difficult for the substrate to bind to the active site, they don’t change the active site and can be removed by increasing substrate concentration