Chapter 35: Transport in Plants Flashcards
What do plants need water for?
photosynthesis, transporting solutes, cooling and internal pressure for support
water uptake does through cells through…
osmosis
water potential
overall tendance for a solution to the up water from pure water, across the membrane
Water Potential = Solute Potential + Pressure Potential
Solute potential, and water potential are measured in…
megapascals (MPa)
Turgor Pressure
when a flaccid cell is placed in pure water, water moves into cell due to negative solute potential. Cell cant expand because of cell wall, so internal pressure increases
Bulk Flow
over long distances in xylem and phloem, flow of water and dissolved solutes is driven by gradient pressure potential
Aquaporins
membrane proteins that water can pass through rapidly
Electrochemical gradient
combination of electrical and concentration gradients
proton pump
moves protons out of cell, against a gradient
apoplast
(fast lane)– cell walls and intercellular spaces form continuous meshwork that water can move through
symplast
(slow lane)– water passes through cells via plasmodesmata
plasmodesmata
membrane channels that cross walls of adjacent plant cells
casparian strips
regions of suberin- impregnated endodermal cell walls that form water-repelling belt
xylem sap
water and minerals end up in xylem
transpiration
water vapor diffuses from leaf to atmosphere through stomata
