Topic F- Plant Transport Flashcards
Adaptations of a root hair cell
covered in millions of hairs= big SA
large surface area= exchange of particles can happen quickly ( osmosis, diffusion, active transport)
lots of mitochondria for energy ( ATP) for active transport
How is water absorbed by the root hair cell
Osmosis
- water potential = inside + outside cell therefore no movement osmosis )
- cell does active transport of mineral ions
- mineral ions concentration goes up inside cell = decrease water potential inside = increase of water potential inside
- therefore water moves by osmosis down the water potential gradient into the cell
- until equilibrium is reached ( back at the beginning )
- volume in cell increases = pressure increasing= process happening in next cell along
adaptations of xylem
thick walls of lignin= waterproof/ stop cell collapsing
dead cells= no cytoplasm/organelles= no obstruction to water flow
what does the xylem transport and from where 2 where
transports - water and mineral ions
one way flow from the root to leaf
travels up the xylem by transpiration pull
definition of transpiration pull/ stream
when water is drawn up the xylem vessel to replace water loss at the leaves
adaptations of phloem
alive cells + thin cytoplasm = so sugar transport doesn’t stop
no nucleus/organelles ( but in companion cell ) = reduces resistance of sugar flow
companion cell= controls everything
sieve plates = control which direction sugar goes in ( movement of substances )
what does the phloem transport and from where 2 where
transports- sucrose + amino acids (food)
2 way flow = from source ( where made) 2 sink ( where used )
between the leaves and other parts of the plant
definition of transpiration
evaporation of water from surface of a plant
when water vapour diffuses into through the stomata from the leaf lowering the water potential inside the leaf
what happens in the leaf ( in terms f water transport and gasses )
xylem = gets water into leaf - which diffuses round in air spaces
water uses = photosynthesis
keeps cell turgid- supports the plant
most goes out of the stomata
guard cells = close at night- no CO2
open in day - water + CO2 in 4 photosynthesis
what 4 factors affect rate of transpiration
- Humidity
- Wind speed
- Temperature
- Light Intensity
how does humidity affect transpiration
increase in humidity ( water potential outside increases) = decrease in transpiration ( cos of reduction in concentration gradient )
how does wind speed affect transpiration
increase wind speed = increase transpiration
wind removes H2O outside leaf= increases concentration gradient
how does temperature affect transpiration
heat = H2O molecule has more energy= moves faster= more evaporation = increase transpiration rate
how does light intensity affect transpiration
increase light= open pore width ( at night stomata closes )= more space = more evaporation= increase transpiration
Describe the transpiration rate experiment
- cut the end of stem diagonally in the water (so no air enter xylem)
- put potometer tube in water and remove all air bubbles
- connect the stem and photometer under the water and make sure form water tight junction
- Do not get any of the leaves wet ( so water can enter through stomata )
- remove connected tube and stem from water + leave bit of tube hanging in water and mark 10cm on tube
- taking hanging bit of tube in water out and block end to create air bubble
- time how long it takes for air bubble travel the 10cm
- the divide distance/ time giving u the rate
- repeat and take an average
what is magnesium need for in plants
to make chlorophyll
what is nitrate needed for
to make amino acids = protein = growth
what is phosphate need for
to make energy
what is osmosis
movement of water molecules across semi permeable membrane from low concentration to high
what is diffusion
movement of particles from high concentration to low, down a concentration gradient until equilibrium is reached
what is active transport
net movement of particles across semi permeable membrane from low to high against concentration gradient.
requires energy
definition of translocation
movement of food substances round the plant through the phloem
