Notes: Thermodynamics
Energy is the capacity to do work.  Kinetic defines the energy due to motion.  Kinetic energy performs work by passing motion on to other matter.  Heat is kinetic E resulting from random molecular movement.  Potential and chemical energy store energy (in molecules) having the capacity to do work.  In this case, E is possessed because of location or structure.  Chemical E can be tapped when a chemical rxn rearrange molecules such that potential E is changed into kinetic E.

Metabolism is the rate of Energy (E) consumption (aka the rate at which you burn calories).
Catabolic pathways release E through hydrolysis (by inserting HOH to separate 2 pieces).
e.g.  cellular respiration

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Catabolic
(larger to smaller molecules)
\/

/\
Anabolic
(smaller to larger molecules)
|

Anabolic pathways store E through condensation (removal of HOH to join 2 pieces).
e.g. photosynthesis

Thermodynamics means "the energy transformations that occur in matter.

open system
E is transferred between system and environment

closed system
system isolated from environment
has a cyclical E flow

1st Law of Thermodynamics
E is constant. (Conservation of Energy)

2nd Law of Thermodynamics
Every E transfer or transformation increases entropy.

Life does NOT follow the 2nd Law.  Life is an open system.

entropy
the measure of disorder

enthalpy
total heat in a system

G = H - TS
free E = enthalpy minus (temp times enthalpy)
free E = total E minus the Intensity of random motion

spontaneous reaction
takes place without the addition of any more E.  It can only occur if it increases entropy (disorder) in the universe

free E
E available to do work
heat = only E incapable of work

equilibrium
as approaching equilibrium, free E decreases

reactions
exergonic reactions are catabolic
endergonic reactions are anabolic
(see "Nature")

complex systems
tend to break down because they require a lot of E to maintain
living complex systems are maintained by ingestion

Bioenergetics
how organisms manage their energy resources

simplifying a system
as you simplify a system, you lose more and more E

balance
All organisms strive for E balance, equilibrium is finally maintained when you die

catabolism
loses free E (stored E) to allow it to do work

anabolism
stores E (increases free E and chemical E)

oxidation reaction
loses e-

reduction reaction
gains e-

together they are "redox reactions"

Energy Coupling (ATP Cycle, below)
transfer of E from catabolic to anabolic rxns

Nature runs Downhill what is "G"?
1.exergonic = spontaneous (deltaG < 0)
2.endergonic = nonspontaneous (deltaG > 0)
3.equilibrium = death because no work can be done (deltaG = 0)
4.key to disequilibrium = product of a rxn is the reactant in the next step on the metabolic pathway

ATP provides the free E for all (most) cellular work
Adenosine TriPhosphate is composed of high E phosphate bonds
Unstable
ATP is unstable because it has 3 negatively charged phosphate groups linked together sequentially.  The negative charges are constantly pushing away from each other.

phosphorylated intermediate
transfer of phosphate group to keep the deltaG negative (to keep using/losing free E to do work).  To the right is an example.

1. ATP transfers a Phosphate (p) to Amino Acid (AA)
2. Another AA takes the place of P
3. Result:  a polypeptide and free P for oxidative phosphorylation in the ATP Cycle.

Next:  "Enzymes and Regulation."