Biochemistry Flashcards
what is the definition of a biological catalyst?
speeds up the rate at which a reaction reaches equilibrium but does not effect the position of equilibrium
what do biological catalyst do in terms of activation energy and transition states?
they lower the activation energy and stabilise the transition state
what are enzymes without a cofactor called?
apoenzymes
what are enzymes with a cofactor called?
holoenzymes
what does a substrate bind to?
active site of an enzyme
what is the definition of induced fit?
binding of substrate induces a conformational change in shape of enzyme resulting in complimentary fit
what protein carries out phosphorylation?
protein kinases
what is vmax?
vmax = maximal rate of reaction at unlimited concentration of reactants
the intersection of the straight line with the y axis
what is Km?
Km = michaels constant, 50% vmax
the lines intersection with the x axis
why are lineweaver burk plots issued instead of hyperboles? (michealis menten)
it’s easier to read vmax and Km
what happens in reference to vmax and Km during competitive inhibition?
competitive - binds to active site
vmax remains the same
Km varies
what happens in reference to vmax and Km during non competitive inhibition?
non-competitive- binds to site other that active site
vmax varied
Km stays the same
what are characteristics of cholesterol?
present in cell membrane
component of myelin sheath
precorsor molecule for steroid hormones, viteman D and bile acid
what are the characteristics of triglycerides?
present in all cell membranes/lipid bilayer
highly concentrated energy stores
