lab 6 terms Flashcards
water potential
the stored energy of water molecules in a given area
capillary forces
the forces that cause water to flow through narrow spaces (such as tracheary elements) due to the properties of water - cohesion and adhesion
cohesion
the strong attraction of water molecules to each other due to hydrogen bonding
adhesion
the attraction of water molecules to hydrophilic molecules, i.e., the cellulose of plant cell walls
osmosis
the movement of a solvent (usually water) from a region of low solute concentration to a region of high solute concentration through a selectively permeable membrane
aquaporins
proteins embedded in the plasma membrane; form pores to facilitate the movement of water across the plasma membrane
symplast
the interconnected protoplasts and their plasmodesmata in living plant tissue; allows the movement of water across tissue, by moving inside the cell
apoplast
the non-living parts of plant tissues, the cell walls and intercellular spaces; allows the movement of water across the tissue by moving in the cell walls and intercellular spaces
suberin
fatty material located within the cell walls of cork cells and the Casparian strip of endodermal cells
Casparian strip
a band of suberin and lignin within the transverse and radial primary cell walls of cells of the endodermis
water potential gradient
the difference in water potential between two regions; water will flow from an area of higher water potential to an area of lower water potential
transpiration (evapotranspiration)
the loss of water vapor from a plant, mostly through the stomata of its leaves
active transport
energy-requiring transport of a solute across a plasma membrane against a concentration gradient
turgor pressure
the pressure within a cell due to water moving into the cell by osmosis
callose
a carbohydrate; a component of the cell wall near the sieve plate of a sieve tube element of phloem tissue; may develop in reaction to injury
