Lecture 3 Free energy of hydrolysis.pdf

BIOC*4520: Metabolic Processes Energy, metabolic processes and thermodynamics Gibbs equation ΔG = ΔH - TΔS. Organisms Perform Energy Transductions to Accomplish Work to Stay Alive  Six Kingdoms of Life Defined by Organism, Cellular, and Molecu...

BIOC*4520: Metabolic Processes Energy, metabolic processes and thermodynamics Gibbs equation ΔG = ΔH - TΔS. Organisms Perform Energy Transductions to Accomplish Work to Stay Alive  Six Kingdoms of Life Defined by Organism, Cellular, and Molecular Differences Six kingdoms Cellular organization Archaea Unicellular prokaryote Bacteria Unicellular prokaryote Protista Unicellular eukaryote Fungi Uni- or Multicellular eukaryote Plantae Multicellular eukaryote Animalia Multicellular eukaryote Organisms Can Also Be Classified by Different Energy and Carbon Sources Metabolism Is the Sum of All Chemical Reactions in the Cell Life on earth - constant temperature and pressure (1 atm.), so we can confine our bioenergetics analysis to consideration of Gibbs free energy ΔGo. A reaction is favorable if the change in Gibbs free energy (ΔGo) is negative, i.e. if the free energy of the products is less than the free energy of reactants. A favorable, spontaneous reaction A+B ⇄ C+D occurs if: GC + GD < GA + GB  Equilibrium and ΔG° Measure Spontaneity of a Reaction In biological systems R = gas cst. = ΔG’o or ΔGo’ used 0.00831 for ΔGo kJoule/mole/K Under standard conditions, e.g. start with 1 M of A & B Free Energy, or the Equilibrium Constant, Determines the Spontaneity of Processes TABLE 13-3 Relationships among K'eq, G˚, and the Direction of Chemical Reactions Starting with all components at When K'eq is... G˚ is... 1 M, the reaction... >1.0 negative proceeds forward 1.0 zero is at equilibrium