Week 4

Gibbs Free energy

energy to do work, measure of reaction favorability/spontaneousity

neg. means exergonic, favorable, spontatneous

pos. means endergonic, unfavorable, non-spontaneous

=0 means equilibrium

ΔG = Gproducts - Greactants

Enthalpy

potential energy in bonds of molecules

ΔH = Hproducts - Hreactants

neg. means exothermic, spontaneous, reactants have more PE

pos. means endothermic, non-spontaneous, products have more PE

long. weak bonds have higher PE

Entropy

measure of disorder (dispersal of energy)

neg. means less disorder, less spontaneous, unfavorable

pos. means more disorder, more spontaneous, favorable

gibbs free energy equation

ΔG = ΔH - (T)(ΔS)

kinetic energy

energy of motion, stored as thermal energy in molecular level

potential energy

energy stored in position, stored in chemical bonds at molecular level

energetic coupling

energy yield of exergonic used to power endergonic

occurs via electron transfer or electron shifting

catabolic reactions (break) release energy to power anabolic reactions (build)

ATP hydrolysis is an example of spontatneous reactions

higher PE due to 3 weak bonds with phosphate groups with 4 neg. charges in groups causes phosphate groups to repeal, causing PE to increase (highly exergonic)

redox reactions as energetic coupling

Oxidation: loss of electrons, electron donor, exergonic half, lowers PE of reactant

Reduction: gain of electrons, electron acceptor, endergonic half, increases PE of reactant

proteins use __ to power the coupling of exergonic and endergonic reactions

ATP