- Metabolism - sum of all anabolic (building complex substances from simpler subunits) and catabolic (breaking down of complex substances) processes in a cell or organism.
Laws of Thermodynamics:
- The total amount of energy in the universe is constant. Energy cannot be created nor destroyed but only converted from one form into another.
- The entropy (measure of randomness or disorder in energy or in a collection of objects) of the universe increases with any change that occurs.
Entropy increases when:
- solid reactants become liquid or gaseous products
- liquid reactants become gaseous products
- fewer moles of reactant molecules form a greater # of moles of product molecules
- complex molecules react to form simpler molecules
- difusion
- Gibbs Free energy: energy that can do useful work; mostly stored in ATP in living cells
- In order to break bonds between the reactants, activation energy must be reached.
- Exergonic reaction: spontaneous; decrease in Gibbs free energy
- Endergonic reaction: not spontaneous; increase in Gibbs free energy
- Anabolic reactions create order out of chaos in a local area of the universe at the expense of creating a greater amount of disorder in the universe as a whole.
Redox reaction: combination of oxidation (atom loses electrons) and reduction (atom gains electrons), often occurring in a chain reaction.
Reducing agent provides electrons and oxidizing agent takes electrons.
- Allosteric sites are receptor sites:
Activator: stabilizes the active form of the enzyme
Inhibitor: stabilizes the inactive form of the enzyme
*Textbook p.58-77
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