lec 4 Flashcards
what is the diff bw a frog and a toad? what implications does this have for their adaptations?
frogs prod way more LDH, which catalyzes [idk what substrate ngl] for energy –> frogs have energy more readily available.
this plays into their defensive adaptations: frogs direct more energy into escaping via physical traits, whereas toads spend more energy on defensive chemical mechanisms such as poisons
what is the reaction catalyzed by lactate dehydrogenase? simply? fully?
simple: pyruvic acid + 2H –> lactic acid, via LDH
full: pyruvic acid –> lactic acid, via LDH, through NADH2 –> NAD [see notes for image]
if i take a container full of enzymes and add substrates, what happens? how can i tell when the solution is fully saturated? what exactly does an enzyme do anyways?
enzymes will begin to act on substrates. solution is fully saturated at the point at which an enzyme finishes with one substrate and instantly has another to work on. this state is achieved when reaction = reverse reaction
o btw enzymes are said to accelerate reaction velocity (V)
what is Km? what is its relationship to Vmax?
Km is the affinity for binding an enzyme has, such that 1/2 Vmax is attained.
the smaller a Km is, the the less time it takes to reach 1/2 Vmax –> the higher affinity the enzyme has
what happens when u double the amount of enzymes in a solution?
Vmax halves; Km is unchanged [actually unsure about that first part] [no im a fucking genius actually]
how can you change Km?
Km is the affinity of an enzyme binding to a substrate –> u need to change the enzyme somehow (allosteric inhibitors or modulators)
why do we shift things to a lineweaver-burke plot?
gives us Km and Vmax using basic calc and formulas
how does competitive inhibition work? what does this do to Vmax? Km?
inhibitors compete w substrate to bind to enzyme. strength of inhibitor depends on concentration relative to substrate
Vmax is unchanged; effect on Km is incr it (decr in binding affinity)
how does noncompetitive inhibition work? what does it do to Vmax? Km?
molecules bind to allosteric sites on the enzyme, inhibiting its function by causing conformational changes or other such alterations that prevent it from doing its gotdamn job
effect on Vmax is that it decr it; Km is unchanged
how does mixed inhibition work? what does it do to Vmax? Km?
an agent that causes a decrease in the functionality of an enzyme, while also reducing binding affinity [???]
idk ig it slows reaction rate and also decr binding affinity
effect on Vmax is that it decr; effect on Km is that it incr
what is covalent activation? what is a prominent example?
turning on an enzyme via covalent bonding. prominent example is phosphorylation, which incr Vmax
