Unit 1 Bioenergetics Flashcards
entropy
(S)
randomness associated with a given system
enthalpy
(H)
measure of heat content (thermodynamic potential) of a system
free energy
the amount of thermodynamic energy in a system that can be converted into work at a given temp and pressure
high energy compounds
compounds with bonds that release greater than 7 kcal/mol of energy when broken
(∆G= -7; chemical energy of greater than 7 kcal/mol)
Oxidation-reduction reaction:
a chemical reaction involving the transfer of electrons away from one or more compounds (the oxidized compounds) to one or more other compounds (the reduced compounds)
1st law of thermodynamics
energy is neither created nor destroyed. Energy can be converted into different forms but is always conserved
2nd law of thermodynamics
entropy of the universe is constantly increasing
kinetic energy
- radiant energy
- thermal
- mechanical
- electric
radiant energy
- kinetic energy
- carried in photons from sun, the ultimate source of all forms of energy in living systems
thermal energy
- kinetic energy
- protein molecules function optimally at a particular temperature or need certain thermal energy to function
mechanical energy
- kinetic energy
- movement of cells and cell components
electrical energy movement
- kinetic energy
- movement of charged particles down gradients of electric potential
potential energy
- stored in chemical bonds
- stored in concentration gradients
- stored in electric fields from charge separation
- stored in redox pairs
-∆G
- reaction is thermodynamically favorable
- will occur spontaneously at any temp
∆G is
Gibbs free energy constant
+∆G
- rxn not favorable
- will not occur spontaneously at any temp
Gibbs free energy equations
∆G = ∆G0 + (RT * ln [PRODUCTS]/[REACTANTS])
b) ∆G0 = -RT * ln (Keq)
c) ∆G = ∆H – (T * ∆S )
∆H is
change of enthalpy (of bond energy) of a reaction
exothermic rxn
-heat released
∆H is negative (favorable)
endothermic rxn
-heat is absorbed
∆H is positive (unfavorable)
∆G < 0
spontaneous
