transport in cell Flashcards
diffusion is the……
is the movement of particles from a high concentration to a low one , describes the movement of particles in fluid (liquids and gasses)
definition (c0z and urea)
carbon dioxide and urea can move in and out of the cells across cell membranes via the process of diffusion
carbon dioxide where does it diffuse
carbon dioxide diffuses in the bloodstream into the lungs during cell respiration
oxygen diffuses from the lungs into the bloodstream
urea where does it diffuse into
urea is a waste product of cells
diffuses from cells into the blood for excretion by the kidneys
factors of diffusion can be affected by these
Temperature- Higher the temperature that faster the rate of diffusion
concentration gradient- the concentration gradient is linked to the difference in concentration between two areas . the bigger the difference in the two areas the faster the rate of diffusion and the greater the concentration
membrane surface area -The larger the surface area of the membrane that a substance is diffusing through (eg membrane around the cell) the faster the rate of diffusion
How is the root cell adapted for absorbtion of water and nutrients?
The large surface area of root hair cells increase the rate pf diffusion allowing more water and nutrients into the plant
EXCHANGW SURPHACES
they are adapted to maximise the efficiency of gas and solute
exchange surfaces contain of…
large surface areas - allows more of a substance to diffuse at the same time
ventilation- in animals if gas is exchanged the surface is ventilated ( through breathing) maintaining high concentration and increasing the rate of exchange
Blood supply=where substances are exchanged through blood in animals , exchanged surfaces are densely packed with
These blood vessels replenish the blood supply to maintain the high conc gradient by bringing in new blood as diffusion starts to even out the concentration
Thin membrane -reduces thhe diffusion distance
examples of exchanged surfaces
SMALL INTESTINE -small intestine is adapted for exchanging nutrients between digested food in small intestine and the blood
LUNGS -adapted for exchanged CO2 and oxygen between blood and air
GILLS =adapted for exchanging oxygen that’s dissolved in water with the co2 in the fishes bloodstream
ROOTS= adapted by taking water and minerals from soil around them
LEAVES = are adapted by exchanging carbon dioxide and oxygen between the leaves and surrounding air
what is the small intestine adapted for….
exchanging of the nutrients between the digested food and blood
OSMOSIS
diffusion of water across a partially permeable membrane from a dilute solution to a concentrated solution
whats a partially permeable membrane ?
allows water through however no larger molecules dissolved in water pass through
WATER MOVEMENT
Wter will move to make the concentrations the same on both of the sides of membrane
when there is a lot of water molecules on one side of partially permeable membrane but not many on the other water will move from a dilute to a concentrated solution
NET MOVEMENT OF WATER
important to remeber that water molecules will move throught the membrane in different diretions but the net overall will be from dilute to concentrated
independant variable and dependant variable in an osmosis experiment
independant variable =you can control for example in osmosis experiment you change the concentration of the sugar solution each time
dependant variable = is a variable that you measure as an outcome of the experiment it would be the change of mass of object being used
