Bioenergetics LO Flashcards
Define Entropy
randomness associated with a given system
Define enthalpy
measure of heat content (thermodynamic potential) of a system
Define free energy
the amount of thermodynamic energy in a system that can be converted into work at a given temperature and pressure
Define high energy compounds
compounds with bonds that release greater than 7 kcal/mol of energy when broken (deltaG= -7; chemical energy greater than 7 kcal/mol)
Define oxidation-reduction reaction
a chemical reaction involving the transfer of electrons away from oxidized compounds to reduced compounds
What is the 1st law of thermodynamics?
energy conservation (energy cannot be created or destroyed, only converted to other forms)
what is the 2nd law of thermodynamics?
the entropy of the universe is constantly increasing (any given set of reactions that occur simultaneously in a system must increase the overall entropy)
Describe kinetic energy
energy of motion (radiant, thermal, mechanical, electric)
Describe potential energy
energy stored within a system due to configuration or position, can be converted to kinetic energy to perform work
describe radiant energy
carried in photons from sun, the ultimate source of all forms of energy in living systems
describe thermal energy
kinetic energy of molecules (molecular translation, rotation, vibration, e- spin, translation, and nuclear spin) proteins function at an optimal thermal energy
describe mechanical energy
potential and kinetic energy within a mechanical system, discussed within the confines of cellular movement of charge particles down gradients of electric potential
describe electric energy
energy movement of charged particles down gradients of electrical potential
describe chemical energy
energy stored in chemical bonds
how do you calculate deltaG?
∆G0 + (RT * ln [PRODUCTS]/[REACTANTS])
how to you calculate deltaGprime?
- RT ln (Keq)
how do you calculate deltaG?
∆H – (T * ∆S )
what is the spontaneity of this reaction? ∆G<0
spontaneous
what is the spontaneity of this reaction? ∆G>0
not spontaneous
what is the spontaneity of this reaction? ∆G=0
at equilibrium
what does positive entropy do to change the spontaneity of a reaction? (hint use ∆G = ∆H – T ∆S)
increases the spontaneity of the reaction (decreases ∆G)(-∆H = exothermic)
what does a negative entropy do to change the spontaneity of a reaction? (hint use ∆G = ∆H – T ∆S)
decreases the spontaneity of the reaction (increases ∆G) (∆H = endothermic)
what does a negative enthalpy do to change the spontaneity of a reaction? (hint use ∆G = ∆H – T ∆S)
increases the spontaneity of the reaction (decreases ∆G)
what does a positive enthalpy do to change the spontaneity of a reaction? (hint use ∆G = ∆H – T ∆S)
decreases the spontaneity of the reaction (increases ∆G)(+∆S = increased entropy)
how do you calculate ∆E for a reaction?
subtract the Eo of the electron donor from the Eo of the electron acceptor.
when is Eo of a molecule high?
when the molecule is more electronegative
when is Eo of a molecule more negative?
when the molecule is more electropositive
what equation do you use to calculate gibbs free energy using redox potential?
∆G = -nF∆E n = #of electrons transferred F = Faraday's constant ∆E = difference in reduction potential in volts
what does coupling of a reaction mean?
the SUM of gibbs free energy of 2 or more reactions to determine the spontaneity of the reaction (ex. +∆G can be spontaneous if paired with -∆G of greater absolute value)
What is the high energy bond in acetyl Co-A?
thioester bonds C-S
what is the high energy bond in ATP?
phosphoanhydride bonds (P-O-P)
what is the high energy bond in phosphocreatine?
P-N
what is the high energy bond in phosphoenolpyruvate?
C-O-P
What is considered high yield currency in bioenergetics?
bonds that are easy to use, break, and reform.
