Bioenergetics & Metabolism

Bioenergetics & Metabolism

1. Free Energy

   • the amount of internal energy of a thermodynatic system that is available to perform work
   • Laws of Thermodynamic
     • a law governing the relations between states of energy in a  closed system
     • 1st Law: Law of Conservation of Energy
       • the change in the internal energy of a system is equal to the sum of the heat added to the system and the work done on it
       • one of three thermodynamic laws
     • 2nd Law
       • n a natural thermodynamic process, the sum of the entropies of the interactingthermodynamic systems increases
       • one of three laws of thermodynatic
     • 3rd Law
       • The entropy of a system approaches a constant value as the temperature approaches absolute zero.
       • one of three thermodynamic laws
   • Gibbs Free Energy
     • a measure of the potential for reversible or maximum work that may be dome by a system at constant temperature and pressure
     • G = H - TS
       • change in gibbs free energy equals to change in enthalpy minus change in temperature times entrophy Relationship: Equation to get gibbs free energy
       • G = Gibbs Free Energy
         • a measure of the potential for reversible or maximum work that may be dome by a system at constant temperature and pressure
       • H = Enthalpy
         • a quantity associated with a thermodynamic system, expressed as the internal energy of a system plus the product of the pressure and volume of the system, having the property that during an isobaric process, the change in the quantity is equal to the heat transferred during the process
       • T = Temperature
         • a measure of the warmth or coldness of an object or substance with reference to some standard value
       • S = Entrophy
         • a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work
     • Negative
       • quantity below zero
       • One of two possible values of gibbs free energy
       • Spontaneous
         • coming or resulting from a natural impulse or tendency; without effort or premeditation; natural and unconstrained; unplanned
         • we can know when the result of gibbs free energy is negative, the reaction is spontaneous
       • Exergonic reaction
         • a reaction in which energy is released during the process of the reaction
         • when the result of gibbs free energy is negative, the reaction is exergonic reaction
       • Catabolic
         • destructive metabolism; the breaking down in living organisms of more complex substances into simpler ones, with the release of energy
       • Cellular Respiration
         • the series of metabolic processes by which living cells produce energy through the oxidation of organic substances
         • example of negative gibbs free energy
     • Positive
       • quantity above zero
       • One of two possible values of gibbs free energy
       • Non-spontaneous
         • a reaction which cannot occur without the input of work from an external source
         • we can know when the result of gibbs free energy is positive, the reaction is non-spontaneous
       • Endergonic reaction
         • a reaction in which energy is absorbed during the process of the reaction
         • when the result of gibbs free energy is positive, the reaction is endergonic reaction
       • Anabolic
         • constructive metabolism; the synthesis in living organisms of more complex substances from simpler ones
       • Photosynthesis
         • the complex process by which carbon dioxide, water, and certain inorganic salts are converted into carbohydrates by green plants, algae, certain bacteria, using energy from the sun and chlorophyll
         • example of positive gibbs free energy

2. Metabolic Strategies

   • the whole range of biochemical processes that occur within us
   • Endotherm
     • an organism that generates heat to maintain its body temperature, typically above the temperature of its surroundings; warm-blooded
   • Ectothermic
     • an organism that regulates its body temperature largely by exchanging heat with its surrounding; cold-blooded