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Cell. Procaryotic: Eucaryotic Membrane system Cytoskeleton + extracellular components. Metabolism. Catabolic reactions: breakdown Sugar----> CO2 + H2O + energy Anabolic reactions: building. Thermodynamics. Study of Energy transformations in a collection of matter
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Cell Procaryotic: Eucaryotic Membrane system Cytoskeleton + extracellular components
Metabolism • Catabolic reactions: breakdown • Sugar----> CO2 + H2O + energy • Anabolic reactions: building
Thermodynamics • Study of Energy transformations in a collection of matter • Light is a type of kinetic energy
Thermodynamics • 1st Law: • Energy can be transferred or transformed NOT created or destroyed • 2nd Law: • Every transfer of energy: heat is lost (increase entropy)
Ecosystem thermodynamics • Energy into an ecosystem as light out as heat.
System stability • 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 • 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
Free energy in a system • G = Free energy (potential energy) • S = entropy • T = absolute temperature in Kelvin (K) • H = system total energy • G = H - TS
Systems energy • Equilibrium: change in G is 0 system performs no work. • Exergonic reaction: spontaneous: net release of energy • Cell respiration of glucose G = -686
Systems energy • Endogenic reaction: requires energy input • Photosynthesis: synth. Glucose G = +686
System energy • Equilibrium = no G. Cell doing no work • Disequilibrium: cell must maintain disequil. To live. • HOW? Cell is open system with surroundings.
Energy coupling • Exergonic reaction drives an endergonic • ATP mediates
Exergonic • Exergonic: net release of free energy. Decrease G: cell respiration - 686
Endogenic • 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 • 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
ATP • Cell does 3 kinds of work: • Mechanical: contract, move cilia, move chromosomes • Transport: pump things across membrane • Chemical work: push endergonic rxn.s
ATP • ATP + H2O = ADP + inorganic Phos. (Pi) • ATP hydrolyzed to ADP • ATP hydrolyzed in beaker: makes Heat
ATP • 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
ATP • Example: • Mechanical work: ATP phosphorylates a motor protein in cell. • Post work: ATP regenerated by cellular respiration
ATP • Example: • Active transport: ATP phosphorylate membrane protein • Example: • Chemical: phosphorylate key reactants
Regenerate ATP • ADP + Pi = ATP + H2O • Endergonic: requires energy