Enzyme Kinetics and Thermodynamics Flashcards
What is Catabolism (exergonic reactions)?
It is a reaction that breaks down complex molecules into simple ones. Which releases energy
An example is Glucose breakdown to Pyruvate
What is Anabolism (endergonic reactions)?
Reaction that synthesis (build up) of complex molecules from simple ones. Which requires energy
An example is Peptide synthesis from amino acids
What is a Important enzyme for induced fit?
Hexokinase
What is the Lineweaver-Burke Plot?
The inverse of the reaction rate is plotted against the inverse of the substrate concentration
What is the Eadie Hofstee Plot?
The rate of reaction is plotted as a function of the ratio between rate and substrate concentration
What is the Michaelis constant?
The concentration of a given substrate which catalyses the associated reaction at half the maximum rate - Km
What does each symbol mean for Michaelis constant?
V = rate of reaction
Vmax = maximal rate of reaction at saturation substrates concentration
[S] = substrate concentration
Km = Michaelis constant, also reflects the affinity of the substrate for the enzyme
In terms of Km with Enzyme substrates?
Small Km = STRONG bonding of substrate to enzyme
High Km = WEAK bonding of substrate to enzyme
In terms of Vmax with Enzyme substrates?
Vmax = maximum velocity or max rate of rxn –>
enzyme in working at full capacity –>
every active site has substrate bound to it
Describe the Zero Law of thermodynamics?
If the ‘body’ A is in thermal equilibrium with the ‘body’ B, and the ‘body’ B is in thermal equilibrium with ‘body’ C. Then the ‘body’ A and the ‘body’ C are also in thermal equilibrium.
What is the 1st Law of Thermodynamics?
The internal energy of an isolated system is constant
What is the 2nd Law of Thermodynamics?
The entropy of an isolated system increases for any spontaneous change
What is the 3rd Law of Thermodynamics?
The entropy, S, of a perfect crystal at the absolute zero of the temperature scale is zero
What is internal energy and equation?
U is the total energy contained within a system
ΔU = w + q
w = work and q = heat
What is enthalpy and equation?
The sum of internal energy and the product of the pressure and volume of thermodynamics system.
ΔU = ΔH - PΔV
What is entropy and equation?
Entropy, S, can be considered as a measure of disorder. Entropy is a state function
For reversible input of heat into a system:
ΔS = q/T
Where heat is not transferred reversibly:
ΔS > q/T
If ΔS = q/T at a constant pressure = ΔH = q
What is Gibbs free energy and equation?
The balancing effect between Enthalpy and Entropy is expressed in the change
ΔG = ΔH - TΔS
What is heat capacity and equation?
Represented by C and measured in Joules per gram per kelvin
Cp = ΔH/ΔT
Cv = ΔU/ΔT
What is Spontaneous?
Occurs naturally. A spontaneous change does not require input of work for it to come about. This does NOT necessarily mean that the process is rapid.
What is Non-Spontaneous?
Requires work in order to be brought about spontaneity arises from a natural tendency for disorder. It does NOT ARISE, however from a tendency towards lower energy.
What is the Equilibrium constant and equation?
K is the value of the reaction quotient
At equilibrium, ΔG = 0, and Q = K therefore:
ΔG = -RTInk
R = 8.314 JK-1 mol-1
What do you add to temperature to change to K?
273.15
