Passive and Active Transport

Types of Cellular Transport Animations of Active Transport & Passive Transport high low Weeee!!! Passive Transport cell doesn’t use energy Diffusion Facilitated Diffusion Osmosis Active Transport cell does use energy Protein Pumps Endocytosis Exocytosis high low This is gonna be hard work!!

Biological Exchanges: Diffusion and Osmosis Diffusion: net movement of molecules from an area of high concentration to an area of low concentration. Example: Sugar or salt dissolving in water. Think Koolaide, instant coffee or tea, Crystal Lite

Molecules are always in motion Difference between gas, liquid and solid

Diffusion Molecules in solution tend to slowly spread apart over time. This is diffusion.

Diffusion [High] [Low] concentrated, high energy molecules diffuse, low energy molecules

Concentration gradient

Diffusion in the Body Occurs across cell membranes The cell membrane is differentially permeable (selective) Movement of water across the membrane is called osmosis

Movement of Molecules Across the Cell Membrane Oxygen and CO2 Water (Osmosis) Ions (Electrolytes) Sugar

Osmosis Osmosis is the movement of WATER across a semi-permeable membrane At first the concentration of solute is very high on the left. But over time, the water moves across the semi-permeable membrane, and dilutes the particles. Video

Animal Cells and Osmosis

Plant Cells and Osmosis Vacuole fills

This requires math… Osmosis Practice

Facilitated Diffusion Molecules that are too large need a specific channel to pass through the membrane High to low

Passive Transport No energy High to low Ends in equilibrium

Active Transport Using ATP Moving against the concentration gradient (moving uphill) Low to high

Types of Active Transport Sodium Potassium Pumps (Active Transport using proteins) 1. Protein Pumps -transport proteins that require energy to do work Example: Sodium / Potassium Pumps are important in nerve responses. Protein changes shape to move molecules: this requires energy!

Types of Active Transport 2. Endocytosis: taking bulky material into a cell Uses energy Cell membrane in-folds around food particle “cell eating” 3. Exocytosis expelling bulky material out of a cell “spitting out” Vesicle fuses with membrane, contents exit

Act It Out Your group of 4 will find a way to act out one of these types of active transport. Make sure you are showing the main components of the transport that you choose. Record your skit and email it to me