Bioenergetics

• A highly coordinated cellular activity in which many multi-enzyme systems cooperate.

  Metabolism
• What are the four main objectives of metabolism?

  1. Obtain chemical energy
  2. Convert nutrient molecules into the cell's own characteristic molecules
  3. Polymerize monomeric precursors into biomolecules
  4. Synthesize and degrade biomolecules which may be required for some specialized cellular functions
• The process of breaking down biochemical fuels to extract energy (energy-yielding process)

  Catabolism
• The process of building up biomolecules to sustain life (energy-requiring).

  Anabolism
• Metabolism in the context of thermodynamics.

  Bioenergetics
• A thermodynamic factor that measures the change in heat content of the reactants and products. (1st law of thermodynamics)

  Enthalpy (AH)
• A thermodynamic factor that measures the change in randomness or disorder of reactants and products. (2nd law of thermodynamics)

  Entropy (AS)
• 1st law of thermodynamics (Law of conservation of energy)

  Energy can be neither changed nor destroyed. It can only be transformed from one form to another.
• Exothermic 


  When heat is released during the course of the reaction; negative AH value
• Endothermic 


  When heat is absorbed during the course of the reaction; positive AH value
• 2nd law of thermodynamics

  The entropy of a system either increases or remains constant but never decreases in a spontaneous universe
• Who developed the Gibbs' free energy?

  Josiah William Gibbs
• This is the energy available to do work.

  Gibbs' free energy
• Gibbs' free energy formula

  AG = AH - TAS
• When AG is negative, the reaction is exergonic and?

  Spontaneous
• When AG is positive, the reaction is endergonic and?

  Non-spontaneous
• If [reactants] and [products] are equal, the standard free energy change (AG^o) is?

  Equal to AG
• If the reaction is at equilibrium (AG = 0), the standard free energy change is?

  -RTlnKeq
• Substances that tend to give up electrons and be oxidized.

  Reducing agents
• Substances that tend to accept electrons and be reduced

  Oxidizing agents
• What is the tendency of a substance to gain electrons and cause the oxidation of another substance.

  Standard reduction potential (E not)
• The more positive the value of E not, the more tendency to gain electrons and be reduced.
• Overall Net Potential 


  The sum of the potentials of half reactions. E not of rdn + E not of oxdn.
• What is the energy currency of the cell?

  Adenosine Triphosphate\
• What are the three main components of ATP?

  Phosphate group, Ribose, Adenine
• Type of ATP metabolism by photosynthesis through photophosphorylation

  Autotrophic metabolism
• Type of ATP Metabolism by cellular respiration

  Heterotrophic metabolism