enzymes Flashcards
what does heating an enzyme past it’s optimum temperature do to it
heating causes bonds to break so active site changes shape so substrate is no longer complimentary and can’t bind
how does a non-competetive inhibitor prevent enzyme activity
it binds to the allosteric site of an enzyme
it changes the shape of the active site so enzyme and substrate no longer complimentary
cannot be overcome by further substrate addition
how do enzymes speed up the rate of natural reactions
they lower the activation energy
how do enzymes lower the activation energy if two molecules need to be joined
being attached to enzyme holds them close together
reducing repulsion between the molecules
so can bond more easily
how do enzymes lower the activation energy if they are catalysing a breakdown reaction
they put strain on the bonds in the substrate so the substrate molecule breaks up more easily
why can only one substrate bind to an enzyme’s active site
as they have an active site that is a specific shape(complimentary) to one substrate
so only one can bind to form enzyme substrate complex
what are the two models of enzyme action
lock and key model
induced fit model
describe the lock and key model
active site and substrate already complimentary shapes
so substrate can bind
describe induced fit model
substrate not only has to be right shape
has to change shape of active site as it binds
so it is now perfectly complimentary.
what are the two ways enzyme activity can be measured
how fast product is produced
how fast the substrate is broken down
name 4 factors that affect enzyme activity
pH
temperature
substrate concentration
enzyme concentration
when would increasing substrate concentration not increase enzyme acitivity
all the enzymes are saturated so there are no free active sites for substrates to bind and no more enzyme substrate complexes can form
what happens to enzyme acitivity past the optimum pH and why
it decreases
due to the H+ ions and OH- ions disrupting the ionic and hydrogen bonds that hold enzyme tertiray structure in place
enzyme is denatured and changes shape
why does increasing enzyme concentration increase enzyme activity
as the more enzymes in solution the more likely a substrate is too collide with an enzyme and form
enzyme substrate complex
when will increasing enzyme concentration not increase enzyme acitivity
if concentration of substrate is limited
there’s comes a point where more enzyme than substrate
so more enzyme has no further effect
