Term
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Definition
| the potential energy that water has in a particular environment compared with the potential energy of pure water at room temperature & atmospheric pressure |
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Definition
| more water than solutes (water goes out) |
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Definition
| the movement of water across membranes in response to differences in solute concentration |
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Definition
| the tendency for water to move in response to differences in solute concentrations |
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| equation that defines water potential if we ignore the effects of gravity |
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Definition
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Definition
| no turgor pressure & thus a pressure potential of 0 |
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Definition
| when an entire tissue loses turgor pressure |
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Term
when air is dry:
1. relatively how many water molecules are present?
2. relative pressure exerted by water molecules?
3. rate of evaporation is _____? |
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Definition
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when air is warm:
1. relative distance between water molecules?
2. relative pressure exerted by water molecules? |
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Definition
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Definition
| causes water to move up through the plant; water potential is highest in the soil, lower in roots, lower yet in leaves, & lowest in the atmosphere |
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Definition
| a single layer of cells; in addition to protecting the root, some produce root hairs |
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Term
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Definition
| greatly increase the total surface area of the root |
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Definition
| consists of ground tissue - usually parenchyma cells - & stores carbohydrates |
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Definition
| a cylindrical layer of cells that forms a boundary between the cortex & the vascular tissue |
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Definition
| layer of cells that forms the outer boundary of the vascular tissue |
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Definition
| narrow band of wax secreted by the tightly packed endodermal cells |
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Definition
| compound that composes the Casparian strip & forms a water-repellent cylinder at the endodermis |
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Term
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Definition
| movement of water up a narrow tube |
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Term
| movement of water up the tube occurs in response to three forces |
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Definition
1. adhesion
2. cohesion
3. surface tension |
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Term
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Definition
| moleculer attraction among unlike molecules |
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Term
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Definition
| a molecular attraction among like molecules |
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Definition
| a concave surface boundary that is formed due to the effects of adhesion, cohesion, & gravity |
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Term
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Definition
| a force that exists among water molecules at an air-water interface |
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Term
| 6 steps in the cohesion-tension theory |
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Definition
1. water vapor diffuses out of leaf
2. water evaporates inside leaf
3. water is pulled out of xylem
4. water is pulled up xylem
5. water is pulled out of root cortex
6. water moves from soil into root |
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Term
| 2 reasons why the transmission of pulling force from the leaf surfaces to the root is possible |
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Definition
1. there are continuous columns of water throughout the plant
2. all of the water molecules present hydrogen bonds to one another (cohesion) |
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Term
| crassulacean acid metabolism (CAM) plants |
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Definition
| open their stomata at night & store the CO2 that diffuses into their tissues by adding the carbon dioxide molecules to organic acids |
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Term
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Definition
| the enzyme, found in all green plants, that initiates the Calvin cycle |
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Definition
| specialized cells in which the Calvin cycle operates in c4 plants |
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Term
| 2 ways in which the location of 14C atoms inside a plant can be documented |
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Definition
1. by measuring the amount of radioactive CO2 emanating from different tissues
2. by laying plant parts on X-ray film & allowing the radioactivity to expose & blacken the film |
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Term
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Definition
| events at source tissues & sink tissues create a pressure potential gradient in phloem; the water in phloem sap moves down this pressure gradient, & sugar molecules are carried along by bulk flow |
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Definition
| when ions or molecules move across a plasma membrane by diffusion - along their electrochemical gradient |
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Term
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Definition
| form pores that selectively admit certain ions |
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Term
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Definition
| work like enzymes, undergoing a conformational change that transports a bound molecule across the lipid bilayer |
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Term
| facilitated diffusion is done by ______ & _____ |
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Definition
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Term
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Definition
| when ions or molecules move across a plasma membrane against their electrochemical gradient |
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Term
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Definition
| proteins that change shape when they bind ATP or a phosphate ground from ATP |
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Term
| 2 types of cotransporters |
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Definition
1. symporters: transport solutes against a concentration gradient using the energy released when a different solute moves in the same direction along its electrochemical gradient
2. antiporters: the solute being transported against its concentration gradient moves in the direction opposite that of the solute moving down its concentration gradient |
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Term
| secondary active transport |
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Definition
| when solutes move through cotransport proteins |
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Term
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Definition
| the membrane that surrounds the vacuole that stores sucrose in plant root cells |
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