Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 13: Transport Processes - Coggle Diagram
Chapter 13: Transport Processes
Diffusion, Osmosis, and Active Transport
Methods
:diffusion
random movement
away from high concentration
osmosis
Membranes
Freely permeable
all solutes diffuse
little biological significance
Completely impermeable
nothing allowed to pass
isolation barriers
Differentially permeable
AKA selectively permeable
certain substances pass
lipid / protein cells
Molecular Pumps
use ATP
force molecules across membrane
active transport
Intracellular Transport
vesicles migrate
fuse with other organelle
Water Potential
Water
free energy
chemical potential
referred to as water potential
symbol Ψ "sigh"
increased
out under pressure
elevated
heated
decreased
reducing pressure
lowering
cooling
3 Components (equation)
pressure potential
effect of pressure
water potential acts with pressure
measured with Megapascals (MPa) or Bors
osmotic potential
effect of solutes
adding solutes decrease waters free energy
number of particles present
matric potential
waters adhesion to nondissolved structures
cell walls, membranes, and soil particles
ONLY decreases water free energy
always negative
Cells and Water Movement
water potential not equal
water moves from cell to solution
osmotic pressure more negative
pressure potential less positive
lysis
burst in pure water
animal cell
plant cells
resist breakage
absorb water
water loss to wilt
incipient plasmolysis
plasmolyzed
not @ equalibrium
continue to loss water
shrinks
Short-Distance Intercellular Transport
symplast
cells communicate
variety of mechanisms
interconnected by plasmodesmata
transfer across plasma membrane
osmosis
fusion
resides in cell wall
both
wall
intercellular space
apoplast
cohesion-tension hypothesis
widely accepted
water loss
transstomatal transpiration
transcuticular transpiration
Control of Water Transport by Guard Cells
water loss to atmosphere
open stomata most important
bulk water movement
light controls guard cells
blue light most important
action matches absorption spectrum
mechanisms overriden by by water stress activated mechanisms