metabolic pathways

• Anabolic


  build up large molecules from small molecules,

  require energy.
• Catabolic


  break down large molecules into smaller molecules,

  release energy.
• metabolic pathways


  can have reversible steps, irreversible steps and alternative routes.
• pore, pumps and enzymes


  proteins embedded in the cell membrane
• key enzymes


  regulate the rate of metabolic reactions
• induced fit


  when the active site changes shape to better fit the substrate after the substrate binds.
• activation energy


  the minimum amount of energy required to start a chemical reaction
• lower

  effect of enzymes on the activation energy
• Substrate


  molecules which have a high affinity for the active site
• product


  molecules which have a low affinity for the active site
• reversible


  reactions where the presence of a substrate or the removal of a product will drive a sequence of reactions in a particular direction.
• competitive inhibitor


  inhibitors that bind at the active site preventing the substrate from binding
• competitive inhibition


  inhibition that can be reversed by increasing substrate concentration
• non-competitive inhibitor


  inhibitors that bind away from the active site but change the shape of the active site preventing the substrate from binding
• non-competitive inhibition


  inhibition that can not be reversed by increasing substrate concentration
• feedback inhibition


  inhibition that occurs when the end-product in the metabolic pathway reaches a critical concentration