Passive Vs. Active Transport in Cells

What is passive transport?• Questions: What part of a cell allows things like sugar,

water, and salt in and out of its environment.• Cell Membrane

• Passive Transport: The movement of substances through the cell membrane without the input of energy (force).

• Acts like a screen door: Air is allowed in, yet bugs are not.• Small particles do not require force.

What is diffusion?• What takes place in your body when a coach ask you to

“warm up”?• The oxygen you are taking in is being passed to all the cells in your

body.

• What allows this process to take place?• Diffusion: A type of passive transport where molecules move from

an area where there is relatively more of them to an area where there is relatively less.

• Diffusion will stop when equilibrium is reached.

• Why do you pull muscles when you don’t warm-up?• The muscle that you hurt did not receive enough oxygen filled cells.

How does temperature effect diffusion?

• Mini-lab– Conclusion: Heat increases the rate of diffusion.

What is osmosis?• Osmosis: The diffusion of water through a cell

membrane.• Water will leave a cell when there is not the same amount of water

inside and outside the cell.• When plant cells loose water the cell membrane pulls away from the

cell wall. – Why do plants become limp in the summer time?

What is active transport?• Active Transport: When an input of energy is required to

move materials through a cell membrane.– How do plant roots get their nutrients?

• Transport protein pulls the nutrient through the cell membrane.

Diffusion/Osmosis Interactive Lab

• http://mw.concord.org/modeler1.3/mirror/chemistry/diffusion.html

EOG Test Prep• Passive vs. Active Transport Review:

http://glencoe.mcgraw-hill.com/sites/0078617898/student_view0/unit5/chapter17/section_2_self-check_quiz-eng_.html

• Cell Process EOG Questions: http://glencoe.mcgraw-hill.com/sites/0078617898/student_view0/unit5/chapter17/standardized_test_practice.html