Cell Transport

• Diffusion is the movement of solute molecules across membrane, down the gradient.
• Simple diffusion is when small or uncharged molecules go through membrane pores.
• Diffusion involves semi-permeable membranes.
• Facilitated diffusion occurs when larger or charged molecules cross using membrane proteins.
• Channel proteins are like tunnels. Or channels, duh!
• Carrier proteins check the shapes of solutes before letting them pass through.
• Osmosis is the movement of solvent molecules, across membrane, down the gradient in direction of higher solute concentration.
• Isotonic osmosis when there is no net water movement and there is the same amount of solute and solvent inside, and outside the membrane.
• Hypotonic osmosis is when there is less solute outside the cell and less water inside the cell. The cell is deprived of water.
• Hypotonic osmosis result in the swelling of the cell, known as hemolysis.
• Hypertonic is too much water in the cell and solute outside the cell, causing water to exit the cell.
• Hypertonic osmosis involves the cell shrinking, known as crenation.
• Passive transport is the movement of molecules across a semi-permeable membrane, from an area of high concentration to an area of low concentration.
• Diffusion and osmosis are kinds of passive transport.
• The 3 types of active transport: cell membrane pumps, Endocytosis, and Exocytosis.
• Protein pumps use ATP to pump ions in and out of the cell.
• Uniports pump one molecule at a time.
• Symports pump 2 molecules at a time, in the same direction.
• Antiports pump 2 molecules at once in opposite directions.
• Secondary active transport involves the Electrochemical Gradient.
• Electric potential is a difference in charge.
• Electric Potential building up results in one side of them membrane having a positive charge and the other having a negative charge.
• A Concentration Gradient forms while the concentration of ions varies across as a gradient.
• Electric potential and the formation of the concentration gradient occur in tandem.
• Concentration gradient and electrical potential are known together as the electrochemical gradient. It stores potential energy.
• Electrochemical gradient stores potential energy for molecule and ion transportation.
• Cell membrane pumps are for small amounts of small substance.
• Endocytosis and exocytosis are bulk transport.
• Endocytosis is vesicle formation.
• Endocytosis involves the cell engulfing substances.
• There are two types of endocytosis: phagocytosis and pinocytosis.
• Phagocytosis is the cell eating. Lysosomes will fuse and break down.
• Pinocytosis is the cell drinking.
• Exocytosis is pretty much the cell taking a shit.
• During exocytosis, the vesicles fuse with the cell membrane then shit outside.