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. Acts like a screen door: Air is allowed in, yet bugs are not. For this reason we say that it is “Semi-Permeable”

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 are relatively more of them to an area where there are relatively fewer. Concentration Gradient: There is an area of high concentration and an area of low concentraion. Diffusion will stop will stop when equilibrium is reached.

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. (this could occur because the molecule is too large or because it is moving against the concentration gradient) How do plant roots get their nutrients? There is more nitrogen in the root of a plant than in the surrounding soil Plants need more nitrogen from the soil to survive 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