Active Transport Do Now 1 Complete Do Now

Active Transport Do Now: 1. Complete Do Now on handout

Lab Questions? • What moved where? • Diffusion, osmosis?

Passive vs. Active Transport Passive Transport Active Transport Substances move High conc. to low Low conc. To high Energy use by the No Yes cell Will cause equilibrium Yes No

Examples of Active Transport • Cell membrane pumps move ions (like Na+ and K+) across the cell membrane. • Cells engulf LARGE particles (like whole cells) – called endocytosis. • Cells release large amounts of substances – called exocytosis.

ATP = Cell Energy • ATP, short for adenosine triphosphate, is the energy source cells use for the work they do. • When we say the mitochondria produces energy for the cell, what we really mean is mitochondria make ATP

How ATP Works Pi DI phosphate TRI phosphate Adenosine P P P Ribose Energy to use ATP = stored Energy ADP = used Energy (like a dead rechargeable battery)

Sodium Potassium Pump Also: http: //www. brookscole. com/chemistry_d/templates/student_resources/shared_resources /animations/ion_pump/ionpump. html

But why? • cells must keep a low concentration of sodium ions and high levels of potassium ions within the cell (intracellular). Outside cells (extracellular), there are high concentrations of sodium and low concentrations of potassium, so diffusion occurs through ion channels in the plasma membrane. In order to keep the appropriate concentrations, the sodiumpotassium pumps sodium out and potassium in through active transport

Think a little more… • Since the Na+/K+ pumps 3 ___ ions out of the cell, but only 2 ____ ions into the cell, the inside of a cell usually has a ________ electrical charge.

Homework! • Read pp. 101 -102 • Finish Labs!!! Due tomorrow!!!