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