Passive and Active Transport 12814 DoNow 12814 What

Passive and Active Transport 12/8/14

Do-Now 12/8/14 �What is diffusion? Provide an example. Use pg. 222 -224 to help.

�Diffusion- movement of molecules from a higher to lower concentration �*Demo �*Note- osmosis is a form of diffusion. Other examples?

Passive Transport �Cell membranes are selectively permeable �Passive transport- transport across a membrane where no energy is required by the cell. The molecules will move from high to low concentration. �Ex/ Diffusion �Ex/ Facilitated diffusion (molecule passes through membrane by transport protein)

Active Transport �Active transport- When a cell must use energy (ATP energy) to move molecules or ions across a membrane. A protein will be involved. �Ion- a charged molecule (Ex/ Na+, Cl-) �Why would a cell need to use energy?

Concentration gradient �Passive transport- moves down a concentration gradient (high low concentration) �Active transport- moves up the concentration gradient (molecule travels from low high concentration)

Passive or Active Transport? 1. 2. 3.

Passive & Active Transport �Make a venn diagram to compare and contrast active and passive transport

Sodium-Potassium Pump �Example of active transport �Animal cell has high K+ concentration inside cells, and low concentration of Na+ �We keep pumping K+ into cells despite the high concentration already in them �We keep pumping Na+ out �Animation �http: //highered. mcgrawhill. com/sites/0072495855/student_view 0/chapter 2/a nimation__how_the_sodium_potassium_pump_work s. html