Free energy

Free Energy

The portion of the system's energy that can do work, driving spontaneous biochemical reactions.

Spontaneous Reaction

A reaction that occurs without needing energy input, characterized by a decrease in free energy.

Delta G (ΔG)

The change of free energy in a reaction, with negative values indicating spontaneous processes.

Exergonic Reaction

Another term for a spontaneous biochemical reaction, which is thermodynamically favorable.

Gibbs Equation

ΔG = ΔH - TΔS

Endothermic Reaction

A reaction that consumes heat, resulting in a positive change in enthalpy.

Equilibrium Constant

The ratio of the concentrations of products to substrates at equilibrium, which remains constant.

Le Chatelier Principle

States that when a dynamic equilibrium is disturbed, the position adjusts to counteract the disturbance.

Reversible Reaction

A reaction that can proceed in both forward and reverse directions.

Entropy

A measure of disorder in a system, which increases during spontaneous reactions.

the reaction will shift backward to form reactants

Q > K

the reaction will proceed forward to form products

Q < K

ΔG is Gibbs free energy change, R is the gas constant, T is temperature, and ln(Q) is the natural log of the reaction quotient

ΔG = ΔG° + RT ln(Q)

Gibbs Free Energy equation in terms of K

ΔG° = -RT ln(K)

K

The equilibrium constant, representing the ratio of product to reactant concentrations, raised to their stoichiometric coefficients.

Q

Represents the ratio of product concentrations to reactant concentrations at any point in a reaction, raised to their stoichiometric coefficients.

R

R is the universal gas constant (8.314 J/(mol·K)

s→ P The products and reactants are at equilibrium, when suddenly some of the products are removed. In what direction will the reaction proceed?

Forward

s→ P Keq= 4. If the concentration P, [P], is 10M, and the concentration of S, [S], is 1M, the forward reaction is:

non-spontaneous

s→ P Enthalpy is negative and the product of Temperature and Entropy is positive. What is the most appropriate description of the spontaneity of the reaction?

Spontaneous