Exam 4 Flashcards
internal functioning of plants
plant physiology
the movement of molecules from an area of higher concentration to an area of lower concentration
diffusion
diffusion of water across a semipermeable membrane
osmosis
different substances diffuse at different rates through this
semipermeable membrane
a mixture in which things are dissolved evenly
solution
the substance things are dissolved in
solvent
the thing dissolved in the solvent
solute
a solution with a solute concentration higher than the cell’s (cell would lose water)
hyptertonic
a solution with a solute concentration lower than the cell’s (cell would absorb water)
hypotonic
a solution with a solute concentration equal to the cell’s
isotonic
when the plasma membrane presses tightly against a cell wall, the plant cell is…
turgid
when the plasma membrane is not tightly pressed against a cell wall, the plant cell is…
flaccid
when the membrane pulls away from the cell wall altogether, which over time may kill the cell , the plant cell is…
plasmolyzed
how is water potential calculated?
water potential = pressure potential + solute potential
what is water potential?
the total pressure driving water in one direction or another
water always moves from an area of __ water potential to an area of __ water potential
higher, lower
what are the three main processes that move water through plants?
1) root pressure
2) capillary action
3) cohesion tension theory
stimulation of movement of water up the roots and lower stim due to
root pressure
the movement of water up a narrow tube due to polar bonding is known as
capillary action
a chain of water molecules joined by hydrogen bonds is pulled up the plant by evaporation through the leaves, this is known as
cohesion tension theory
the evaporation of water out of a leaf which drives water movement through the mesophyll is known as
transpiration
air bubbles break the tension (the pull) of the water column in xylem vessels; the air bubble is referred to as
embolism
the loss of xylem function due to embolism is called
cavitation
in small plants, repairing cavitation involves __ forcing gas bubbles to dissolve
root pressure