Enzymes Flashcards
do enzymes increase or decrease the rate of reaction?
increase
are enzymes catalysts?
yes
what type of catalyst are enzymes and why?
biological catalysts because we find them in living organisms
when a substrate attaches with a enzyme we call it a?
enzyme-substrate complex
once a substrate binds to the active site what does the active site do (Hint:bonds)?
the amino acids on the surface of the active site form temporary bonds with the substrate molecule
when the enzyme catalyses the substrate into product we call it?
enzyme-product complex
How do enzymes increase the rate of reaction?
-decrease the activation energy
-by binding to the reactant molecules (substrate) and allowing chemical bond-breaking and bond-forming processes to happen more easily.
enzymes are what type of protein?
globular protein
explain the induced fit model????????????
it is the theory that the shape of the active site changes in order to fit the substrate molecule that is approaching , As the substrate starts to form bonds with the amino acids in the active site the tertiary structure of the enzyme adjusts so that the active site moulds itself tightly around the substrate, ensuring that the active site fits perfectly to the substrate and the bonds that the substrate forms with the active site helps to catalyse the reaction.
(molecules that are not the substrate can not form the correct bonds to the correct amino acids in the active site so the structure (active site) does not change)
why are enzymes specific for their substrate?
(molecules that are not the substrate can not form the correct bonds to the correct amino acids in the active site so the structure (active site) does not change)
for human enzymes the optimum temperature is around?
40 degrees
what is the effect of temperature on enzymes?
increasing the temp increases the rate of reaction until a point where the optimum temp has passed causing the enzymes to denature.
What does Vmax mean?
when the enzymes are working at its fastest rate
lets say we have a low concentration of enzyme molecules but a very large concentration of substrate describe why the rate of reaction will be low?
because all of the active sites will be colliding with substrate molecules all of the time so at any time a large number of substrate molecules will be unable to collide with a free active site so rate of reaction will be relatively low.
is the substrate the only molecule that can attach to the active site?
no a competitive inhibitor can as well
what can a competitive inhibitor do to the rate of reaction?
will decrease it because while the inhibitor is attached to the active site the substrate cant collide with it so the reaction will be slow.
Penicillin is a competitive inhibitor but it is a irreversible on what does that mean?
means we cannot reverse the effect of these inhibitors by increasing the substrate concentration because once the competitive inhibitor enters the active site it never leaves no matter what the substrate concentration.
what is the difference between a competitive and a non-competitive inhibitor?
non-competitive inhibitors do not bind to the active site of an enzyme but bind to a different site on the enzyme molecule called the allosteric site
what happens when the non-competitive inhibitor binds to the allosteric site?
it causes the tertiary structure of the enzyme to change so the change of the active site changes so it is no longer complementary to the substrate, now the substrate molecule cannot bind to the active site so reducing the rate of reaction
