Bioenergetics Flashcards
Bioenergetics is also called?
This concerns the initial and final energy states of reaction components, not the ___
Thermodynamics
Rate of the reaction (that is kinetics)
Enthalpy is ?
When it is negative, what kind of reaction is it?
Total energy of a system
Negative= exothermic; positive=endothermic
When entropy (S) increases,
Reactions will tend to occur spontaneously in the direction in which S increases
More entropy= more KE
Free energy (G) is?
What is it used to predict?
The relationship between enthalpy and entropy
Used to predict the direction of a reaction (negative is favorable)
What would a graph of an exergonic reaction look like?
Endergonic?
Products would be lower than reactants (net loss of free energy), delta G would be negative (spontaneous reaction)
Products would be higher than reactants (net gain of free energy), delta G would be positive (not spontaneous reaction)
What is happening when delta G=0?
Forward and backward reaction occur at equal rates; reaction is at equilibrium; ratio of products and reactants is always the same at equilibrium
Since endergonic reactions are unfavorable, how are they able to proceed?
It can be coupled to an exergonic reaction where the overall net change is exergonic
Is oxidation endergonic or exergonic?
Oxidation= losing electrons= exergonic
Reduction= gaining electrons = endergonic
What is Eo (standard reduction potential)?
How do electrons flow?
The ability/tendency to gain or lose electrons
Electrons flow from pair with more negative Eo to more positive Eo; more negative = more ability to lose electrons
Two ways ATP is produced from redox reactions?
- Directly from metabolism of glucose (substrate level phosphorylation- glycolysis)
- Transfer of electrons from reduced coenzymes to O2 (oxidative phosphorylation-ETC)
