enzymes Flashcards
what is an enzyme
globular protein
can be regulated reaction specificity
what are ribozymes
have no protein but are catalytic RNA molecules
what is a cofactor
usually what is it
non protein component needed for activity
CHANGES PROTEIN SHAPE
an ion of some sort
what is a co enzyme
what are some examples
produced by vitamin take part in reaction
but don’t alter the shape of a enzyme
FAD, NAD+
what is a prosthetic group
a co factor that doesn’t alter group but is attached closely and is needed to function
all enzymes end in
-ase
what do enzymes do
acceleration towards reaction equilibrium
lower the activation energy
what is the best shape for an active site
the shape is complementary to the transition complex
lock and key is a load of bollocks
how do enzymes reduce activation energy
desolvation - single out substrate from solution
induced fit
entropy reduction
what happens if you add more substrate
a higher initial reaction rate and more product
what is the initially reaction velocity called
V0
when do you reach Vmax
when you have saturated all enzymes with substrate
do you ever reach Vmax
not really
what dose a larger Km indicate
a less stable enzyme substrate complex
what dose a smaller Km value indicate
a more stable enzyme substrate complex
what is Km
the substrate concentration to reach 1/2 Vmax
so what dose
Vmax tell us
Km tell us
Vmax - fast - higher the better
Km - fit - the higher the number the less the affinity - faster
what the two Isozymes that catalyse glucose + ATP = glucose-6-phospahte
glucokinase
hexokinase
where is glucokinase located
in the liver
where is the hexokinase located
everywhere else in the body