Biochemistry: Enzyme Kinetics Flashcards
what changes can result in a major implications for disease in terms of enzymes
distribution, abundance, efficiency
what can enzymes be used for in the lab
to develop diagnostic tests and drugs
in terms of enzymes activity, what is V
the no. of moles of a substrate converted per second
in terms of enzymes activity, what is Vmax
the maximum rate of enzyme activity (at infinite [S])
in terms of enzymes activity what is, what is half Vmax
the half-maximal rate of enzyme activity
draw the equation showing enzyme activity
E + S -K+1-> ES -K+2-> E + P
how do you measure Vmax
measure the initial reaction velocity at a known [S] and then increase [S] recording the reaction rate
what is the Michaelis constant
Km - the [S] at which the rate 1/2Vmax
does reaction rate ever reach Vmax
no
how would you calculate Km and Vmax for a true result
convert the results onto a straight line graph
what does a low Km mean
little substrate is needed to ilicit a have Vmax response
what does a high Km mean
a lot of substrate is needed to ilicit a have Vmax response
give an example of a reaction with a low Km and why
- energy production in RBCs
- maintains the reaction even if there is a low glucose conc.
give an example of a reaction with ah igh Km and why
- Proline Hydoxylases, need O2 to regulate transcription factors
- allows O2 sensitive O2 sensing over physiological O2 ranges
what disease can a loss of proline hydroxylase result in
Monge’s Disease +/- Von Hippel Lindaw Syndrome
what are the 2 types of reversible inhibition
competitive and non-competitive
what type of inhibition can be irreversible
non-competitive
what is irreversible non-competitive inhibition
inihibtion irreversible
- usually via fomration or breakage of covalent bonds in the active site
what happens to Km and Vmax in competitive inhibition
Km varies Vmax doesnt
what happend to Km and Vmax in non-competitive inhibition
Km stays the same, Vmax varied
how does feedback inhibition work
end products of a reaction inhibits the rate-limiting enzymes of a reaction
what type of enzymes dont follow Michaelis-Menten rules
allosteric
what enzymes tend to use feedback inhibition as a form of control
allosteric
allosteric enzymes
changes conformtaion when effector binds
in allosteric enzymes and increase in [S] shows what type of curve
sigmoid
what modulates allosteric enzyme kinetics
allosteric factors
- allosteric inhibitors and activators
what type of enzymes show co-operativity
allosteric
give an example of allosteric enzymes that show co-operativity
- Hb binding to O2, +ve co-operativity
- controlled by CO2, 2,3-BPG, H+
