Cell Transportation

Cell Transportation

1. Enzymes (Type 1)

   • Catalysts: Speeds up reactions without being used up themselves
     • Energy of Activation: the amount of energy the reactants must absorb to become activated and start a chemical reaction
       • Endergonic Reactions
       • Exergonic Reactions: a reaction that releases energy
   • Active Site: 3-D site that substrate will bind to
     • Substrate: molecule that binds with an enzyme, the reactant
       • Induced fit & Hydrolysis Reactions
         • Causes Entropy
           • First Law of Therodynamics
             • Energy cannot be created nor destroyed, only transformed or transferred
           • Second Law of Therodynamics
             • Energy conversions reduce the order of the universe and increase entropy
               • Entropy: the amount of disorder in a system
       • Competitive Inhibitors: blocks active site and active site becomes close
       • Incompetitive inhibitors: change the shape of the active site by binding at a different location
   • Imbedded in membrane
     • Phospholipid bilayer
       • Fluid Mosaic Model
       • Made of tails of lipids (hydrophobic) and the heads (hydrophilic) that attract water molecules
     • Enzymes
       • 3 types of membrane proteins
         • Receptors
         • Transport
           • Passive Transport
             • Diffusion
               • Molecules always move from an area of [H] --> [L]
                 • No ATP
             • Osmosis
               • The diffusion of water across a semipermeable membrane
                 • No ATP
             • Facilitated Diffusion
               • Transport proteins may facilitate diffusion across membranes
                 • No ATP
           • Active Transport
             • Endocytosis
               • Phagocytosis
                 • cell eating
               • Pinocytosis
                 • cell drinking
               • Receptor- mediated
             • Exocytosis
             • [L] --> [H]
             • Sodium Potassium Pump

2. Energy

   • Potential Energy
     • stored energy
   • Kinetic Energy
     • Energy in motion