Active Transport

Do Now:

1.Complete Do Now on handout

Lab Questions?

• What moved where?• Diffusion, osmosis?

Passive vs. Active Transport

Passive Transport

ActiveTransport

Substances move High conc. to low Low conc. To high

Energy use by the cell

No Yes

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

Adenine

Ribose

P P P

ATP = stored EnergyEnergy to use

ADP = used Energy (like a dead rechargeable battery)

TRI phosphateDI phosphate Pi

Sodium Potassium PumpAlso: 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 sodium-potassium pump pumps sodium out and potassium in through active transport

Think a little more…

• Since the Na+/K+ pump 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!!!