Standard 3: Cell Transport (Chapter 4: Sec. 1 and 2)
Passive Transport (does not require energy!): A. Diffusion B. Facilitated Diffusion C. Osmosis
Figure A. Simple diffusion is where particles can freely flow through the cell membrane(or the phospholipid bilayer) from where they are more highly concentrated to where they are less concentrated. (NO ENERGY REQUIRED)
Figure B. Faciltated diffusion is where particles need help by a protein to cross the membrane where the particles are moving from where they are highly concentrated to where they are less concentrated. STILL NO ENERGY IS REQURED! [Ion Channel Protein (left) and Carrier Protien (right)]
Figure C. Osmosis is the diffusion of water. The picture illustrates osmosis by water flowing from where it is more highly concentrated to where it is less concentrated. AGAIN, NO ENERGY REQUIRED.
Active Transport (Requires energy!): A. Sodium-Potassium Pump B. Endocytosis and Exocytosis
Figure A. Notice how it has the use of the energy molecule ATP as 3 sodium(Na) ions are being pumped out and 2 potassium (K) ions are being pumped in by the large proteins(green) that are placed along the cell membrane.
Figure B. Endocytosis (top) where large particles are brought in the through the cell membrane as excytosis (bottom) shows how large particles are pushed out of the cell through the cell membrane. Both processes require energy.