Cell

Catabolic reactions: breakdown Sugar----> CO2 + H2O + energy

Anabolic reactions: building

Study of Energy transformations in a collection of matter

Light is a type of kinetic energy

1st Law: Energy can be transferred or transformed NOT created or destroyed

2nd Law: Every transfer of energy: heat is lost (increase entropy)

Energy into an ecosystem as light out as heat.

System will move toward stability High energy low entropy wants to shift to low energy high entropy (more stable)

Opposite charges want to go to eachother

Complex molecules want to breakdown

Free energy is the portion of energy that is free to do work…. Not just change temp.

Free E = potential E = potential to do work

G = Free energy (potential energy)

S = entropy T = absolute temperature in Kelvin (K)

H = system total energy

G = H - TS

Equilibrium: change in G is 0 system performs no work.

Exergonic reaction: spontaneous: net release of energy

Cell respiration of glucose G = -686

Endogenic reaction: requires energy input

Photosynthesis: synth. Glucose G = +686

Equilibrium = no G. Cell doing no work

Disequilibrium: cell must maintain disequil. To live.

HOW? Cell is open system with surroundings.

Exergonic reaction drives an endergonic

ATP mediates

Exergonic: net release of free energy. Decrease G: cell respiration - 686

Endogenic reaction: requires the input of energy: photosynthesis

G increase G= + 686

If rxn reaches equilib. No work being done…….no good for cell

Cell respiration: no reach equilibrium because: the products of 1 reaction are reactants of the next.

ATP: mediates the coupling of reactions

ATP: › sugar = ribose› Nitrogenous base: adenine› 3 phosphate groups› 7.3 Kcal/mole of energy per ATP hydrolyzed

› RNA: ribose, nitrogenous base, 1 phosphate

Cell does 3 kinds of work:› Mechanical: contract, move cilia, move chromosomes

› Transport: pump things across membrane

› Chemical work: push endergonic rxn.s

ATP + H2O = ADP + inorganic Phos. (Pi)

ATP hydrolyzed to ADP

ATP hydrolyzed in beaker: makes Heat

Triphosphate tails: each has – charge. All close together: like compressed spring with potential energy

Phosphorylated: the reactant that accepts the phosphate group

Coupling reactions: the phosphorylated molecule is intermediary

Example: › Mechanical work: ATP phosphorylates a motor protein in cell.

› Post work: ATP regenerated by cellular respiration

Example: Active transport: ATP phosphorylate membrane protein

Example: Chemical: phosphorylate key reactants

ADP + Pi = ATP + H2O Endergonic: requires energy