Make your own free website on


  1. Active Transport: The pumping of individual ions or other molecules across a cellular membrane from a region of low concentration to a region of high concentration.  Ions are pumped against the concentration gradient.  Because the ion or molecule is moved in a direction other than the one in which simple diffusion would take it, the transport process requires energy, which is usually supplied by ATP.
  2. Metabolism: The sum of all the reactions that occur in a living organism.
  3. Energy: The ability to do work.  Measured in Joules.
  4. Catabolism: The metabolic reactions in a cell that result in the breakdown of complex molecules into simpler compounds.  This usually has a release of energy.  
  5. Anabolism: The opposite of catabolism.  It is the constructive part of metabolism, where complex molecules are built up.
  6. Aerobic Metabolism:  Metabolism that occurs that requires free oxygen.
  7. Anaerobic Metabolism: Metabolism that can occur without the presence of oxygen.  
  8. Enzymes:  Agents that perform catalysts in living organisms.  They also help to speed up reactions.