Energetics Flashcards
Define: Entropy
Measure of the microscopic disorder within the system
Define: Enthalpy
Measure of the total energy of a thermodynamic system
Free Energy
Amount of work that can be extracted from the system
High Energy Compounds
NADH, Glucose, ATP, lipids, carbohydrates
Oxidation-Reduction Reaction
Reaction involving transfer of electrons and change of atoms’ oxidation state
1st Law of Thermodynamics
Energy can neither be created nor destroyed (only transformed)
2nd Law of Thermodynamics
Entropy of the universe is always increasing
What are the 4 forms of kinetic energy?
Radiant: carried in photons from the sun
Thermal: protein molecules function optimally at a certain temp
Mechanical: movement of cellular components
Electric: movement of charged particles down gradients
Where is potential energy stored? Hint: 4
Chemical bonds, concentration gradients, electric fields (from charge separation), redox pairs
What are the ΔG equations?
ΔG = ΔG° + RT*ln( [prod] / [react] ) ΔG° = -RT*ln( Keq ) ΔG = ΔH - TΔS
When free energy is ____________ the reaction will be spontaneous at standard conditions.
negative. NOTE: does not tell you the speed (kinetics) at which the reaction will occur
When Keq > 1, ΔG is ________
negative. Reaction proceeds forward
When Keq < 1, ΔG is ________
positive. Reaction goes in reverse
In a biological system, energy can be generated by ….
a series of electron transfers.
What are the two classes of high energy bonds? Give examples of each
Thioester: R–(C=O)–SR’ (e.g. Acetyl-CoA)
Phosphate bonds: P-O-P (PO4 groups in ATP), P-N bonds (phosphocreatine), P-O-C (phosphoenolpyruvate)
