Week 7: Laws governing biophysical and biochemical reactions Flashcards
What is the general form of the conservation of mass?
dm/dt = dm(in)/dt - dm(out)/dt
What is the conservation of component i?
dmi/dt = dmi(in)/dt - dmi(out)/dt + dmi(produced)/dt
What is the formula for Helmholtz free energy?
F = Eint - TS
Eint - internal energy. (Eint = potential energy + kinetic energy)
T - Absolute temperature
S - Entropy
What is the formula for Gibbs free energy?
F = Eint + PV - TS
Eint - internal energy. (Eint = potenital energy + kinetic energy)
T - Absolute temperature
S - Entropy
P - Pressure
V - Volume
When is the Helmholtz free energy equal to the Gibbs free energy?
If during the process the temperature and volume remain constant, then we shall have,
PV =nRT
as a constant. In this case the Helmholtz free energy is equivalent to the Gibbs free energy.
What is the principal of minimal free energy?
A system can alter its status if there is a change in a lowering of the free energy.
A system in an equilibrium state has a minimal free energy.
What is the first law of thermodynamics in formula form?
(53)
What reactions would we like to speed up?
Drug delivery
Cooking
Paint drying
Destruction of air pollutants
Industrial chemical processes
Breakdown of synthetic plastics
What reactions would we like to slow down?
Food decay
Rubber decay
Human aging
Fading of clothes
Fires
Ozone layer destruction
Rusting
What is the definition of reaction rate?
In a biophysical/chemical process a concentration or other property of a reacting system changes with time.
The reaction rate is how fast the reaction is proceeding.
Using thermodynamics, how can an experimental method be used to measure a biochemical reaction?
(54)
Given the reaction constants, how would you calculate the reaction fluxes?
J(C) = k2[C]
J(A) = J(B) = k1[A][B]
What is the order of a reaction defined as?
J = k[C]^n
For a given participating component, i, what is the chemical potential defined as?
(55)
For a general reaction, using the chemical potential derive van’t Hoff’s equation.
(56)
What is the formula for the equilibrium constant?
(57)
What does the equilibrium constant do?
Establishes a relationship between the equilibrium constant and the relevant activation energy for the reaction.
What is the physical meaning of the equilibrium constant?
Rate constant for forward reaction / Rate constant for backward reaction
What is the formula for reaction rate R?
(58)
What is the rate equation?
Rate of reaction is often found to be proportional to the molar concentration of the reactants raised to a simple power. This relationship is called the rate equation.
What is the reaction order?
The power to which the reaction rate changes with changes of the concentration of each participating reactant species is called the reaction order.
How would you experimentally determine the reaction rate of xA + yB –k–> Products.
1) Vary [A], keeping [B] constant and measure rate R.
2) Vary [B], keeping [A] constant, and measure rate R.
What is the empirical rate equation?
(59)
How does the equilibrium constant vary with T?
As T increases, so does the constant?
