Dr Craven - Done Flashcards
What are the units of a unimolecular irreversible reaction rate constant?
per unit time
For a unimolecular irreversible reaction what is the rate of change of A
-k[A]
For a unimolecular irreversible reaction what is the rate of change of B
k[A]
What order is a unimolecular irreversible reaction?
1st order
In a unimolecular reversible reaction, what is important about the transition states of the forward and backward reactions?
They are the same
Why is one reaction more favourable than the other in a unimolecular reversible reaction?
the energy barrier will be smaller in one direction
In a unimolecular reversible reaction what is the rate of A->B?
K1
In a unimolecular reversible reaction what is the rate of B->A?
K-1
How can a unimolecular reversible reaction be described when K1 = K-1
it is at equilibrium
If the reaction A+B->C takes place, what is conditions must A and B meet in in order to make C?
must be in the correct orientation
must have enough energy
If the concentration of A is increased in A+B->C, why will the rate increase?
The chance of a successful collision taking place is increased
In a Bi-molecular irreversible reaction what is the rate of production of C?
K[A][B]
What order is a bi-molecular irreversible reaction?
second
What are the units of the rate constant for a bi-molecular irreversible reaction?
concentration per unit time
What are the units of KD?
concentration
What is the formula for KD in terms of rates?
forward reaction (Kon) / reverse reaction (Koff)
What is the formula for KD in terms of concentration?
[P][L]/[PL}
What does a larger KD mean?
faster forward rate, faster leaving binding site
slower backward rate, slower into biding site
In terms of concentration, what is the amount of fraction bound?
[PL]/[P.tot]
If; KD=2uM, [P.tot]=1uM and [L]=8uM, what is the total concentration of ligand added [L.tot]?
[L]/[L]+KD = 8/8+2 = [PL] =0.8 [L]+[PL] = 0.8+8 = [L.tot] = 8.8uM
What is the Michaelis Menton equation?
(K.cat x [E.tot] x [S]) / ([S] + Km)
What is K.cat?
the rate at which an enzyme will form P if always bound to L
What is Km?
Michaelis constant = how well substrate binds to enzyme
If Km is lower, what does this describe about the binding of the substrate to the enzyme?
better binding
What is a competitive inhibitor?
A molecule which binds to the active site preventing S binding
If a competitive inhibitor binds, what is the effect on Km?
It increases
If a competitive inhibitor binds, what is the effect on Kcat?
It stays the same
