Finals: ENZYMES Flashcards
-catalyst:
speed up chemical reactions
-properties of an enzyme:
peed up chemical reactions, all are globular proteins, all have an active site, can be denatured by heat, substrate specific, can be used over and over, their names end in-ase, function as biological catalysts and increase the rate of a reaction without being consumed by the reaction, speeds up reaction by lowering the energy of activation barrier,
-active site:
where substrate binds to enzyme, where reactions occurs, on surface of enzyme, formed by a few of amino acids,
-denature:
hen globular proteins unravel, can be denatured by heat,
why can’t enzyme work once it is denature
can’t bind substrates, alter specific shape and destroying function (heat), enzyme lose shape, active site changes, can’t bind substrates
-substrate specific:
an only bind and create reaction with specific substrate, shape of enzyme determines which chemical reactions the enzyme catalyzes, active sites fit only specific substrate molecules
-substrate:
enzyme is involved, reactants = substrates, specific reactions that can enzyme acts on
-globular protein:
chain of amino acids folded into a blob
-shape
is critical because it determines function (it creates docking spaces)
-energy of activation barrier:
energy absorbed to contort or weaken bonds in reactant molecules so that they can break and new bonds can form
ES complex:
when substrate is bound, enzyme and substrate complex bond together
-when enzymes denature in heat:
temperature affects molecular motion and its optimal temperature produces highest rate of contact between reactant molecules and enzyme’s active site, higher temperature: denatured enzyme and alter specific shape and destroying function, R groups vibrate fast snf denature, interactions start to break and unravel,
-when enzymes denature in ph:
outside range of 6-8, enzyme may be impaired,
-what factors cause an enzyme to denature:
heat and change in Ph level
ompetitive inhibition:
similarly to substrate, competition for active site
-inhibition:
eversible when weak interactions bind inhibitor and enzyme, no chemical reactions occur
-inhibitors
mimic substrate positions, chemical that interferes with an enzyme’s activity
-examples of inhibitors:
poisons, antibiotics (work on bacterial enzymes, not humans), protease (hydrolytic enzyme, reduce proteins to amino acids) caner (chemotherpay ), HIV drugs (protease)
non competitive inhibition:
non competitive blocker bonds not on active site, change shape of active site, substrate can’t bind
-competitive inhibition
educes enzyme’s productivity by blocking substrates from entering active site, overcome by increasing the concentration of substrate making it more likely that a substrate molecule will be nearby when an active site become vacant
-feed back inhibition:
when have enough product, don’t need to make it any more, product act as inhibitor of one of enzymes early in pathway, most important mechanism that regulate metabolism
-cofactors:
nonprotein helpers, some are inorganic (ions of zinc, iron or copper
-coenzyme:
cofactor is organic molecule, vitamins function as coenzymes
indused fit
enzyme slightly changes it shape causing ti to mold around substrate
product site
leave enzyme, enzymes can be used again
a –> b + C
one substrate, two products
