Biology Chapter 36 Objectives

Biology Chapter 36 Objectives - Chapter 36 Objectives...

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Chapter 36 Objectives: Transport in Vascular Plants 1. This contributes to membrane potential, which allows cations to be driven into the cell. Using cotransport, a transport protein couples the downhill passage of a proton to the uphill passage of another. Through chemiosmosis, this allows proton gradients to enable on process to drive another. 2. Osmosis is the net uptake or loss of water across a membrane. Water potential is a measurement that is affected by the combined effects of solute concentration and physical pressure. 3. Solutes and pressure affect water potential by affecting where water flows. Water flows from regions of higher water potential to regions of lower potential. More solutes increase water potential, and higher pressure also increases water potential. 4. When plant cells are placed into solutions with higher solute concentration, it expands, because the water flows into the plant in order to balance out the solute concentration. When in a low solute solution, the plant size decreases, as the water leaves the plant in order to try to make the concentrations even. When placed into a solution of the same solute concentration, nothing happens. 5. Flaccid means limp. Plasmolyze is when the cell protoplast in a plant shrinks and pulls away from the wall. Turgor pressure is when the cell contents press the plasma membrane against the cell wall. Turgid means to be very firm. 6. Aquaporins are transport proteins that selectively affect the rate at which water diffuses down its water potential gradient. 7. The cell wall, cytosol, and vacuole. 8. Symplast is the continuum of cytoplasm connected by plasmodesmata between cells. Apoplast is the continuum of cell walls plus the extracellular spaces. 9. By the first route, substances move out of one cell, across the cell wall, and into the neighboring cell, which may then pass the substances along to the next cell in the pathway by the same mechanism. This transmembrane route requires repeated crossings of plasma membranes as the solutes ext one cell and enter the next. The second route, via the symplast, requires only one crossing of a plasma membrane. After entering one cell, solutes and water can then move from cell to cell via
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This note was uploaded on 08/29/2009 for the course BIOL 101 taught by Professor Sakji during the Fall '08 term at Linn Tech.

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Biology Chapter 36 Objectives - Chapter 36 Objectives...

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