Diffusion and Osmosis Flashcards
define diffusion
net movement of particles from a region of high concentration to lower concentration, down the concentration gradient.
The steeper the concentration gradient…..
the faster the rate of diffusion for the substance
what affects the rate of diffusion (4 points)
concentration gradient
diffusion distance
temperature
surface area to volume ratio
how does diffusion distance affect rate of diffusion?
the shorter the diffusion distance, the lesser time needed for the substances to travel (shorter –> lesser time) (further –> more time need)
name the two types of diffusion
simple diffusion and facilitated diffusion
define simple diffusion
it is a passive process does not require energy ATP
how is simple diffusion important to living organism? list one example
it is important as it allow the movement of substances for example oxygen and carbon dioxide move in and out of cells through a process called gas exchange (allow needed substances in and remove waste substances out)
define facilitated diffusion
a form of diffusion which involve transport protein present in membrane, which allows more rapid exchange of substances
list the two transport proteins
channel proteins and carrier proteins
is channel protein hydrophilic or hydrophobic
hydrophilic (water loving)
channel protein is hydro___ so what kind of materials can pass through them?
water - soluble material can pass through them as channel protein is hydrophilic
what is the difference between channel protein and carrier protein
channel protein is tube like while carrier protein have two different configuration and it binds the solute before transporting to the other side of the membrane
whats is the similarity between simple and facilitated diffusion
both type of diffusion do not require the use of ATP (adenosine triphosphate)
define osmosis
the net movement of water molecules from a region of higher water potential to a region of lower water potential, through a partially permeable membrane
When solute concentration is low…
water potential is high
when solute concentration is high…
water potential is low
what affects the rate of osmosis (4 points)
Water potential gradient
distance over which water molecules
temperature
surface to area to volume ratio
what happens in a hypotonic solution?
water will enter the cell by osmosis because the water potential outside the cell is higher. (water enters the cell to achieve equilibrium)
when water enter the cell in a hypotonic solution, what happen to the cell (animal)
the cell will swell and lyse (got no cell wall to protect it)
what happens in a hypertonic solution?
water will leave the cell by osmosis because the water potential outside the cell is lower. (water leaves the cell to achieve equilibrium)
when water leaves the cell in a hypertonic solution, what happen to the cell (animal)
the animal cells will crenate and the cell will become dehydrated
when water enters the cells in a hypotonic solution, what happen to the cell (plant)
the plant cell will swell and become turgid but not burst as the plant cell have cell wall to protect it
when water leaves the cells in a hypertonic solution, what happen to the cell (plant)
the plant cell will be plasmolyzed as the plasma membrane of the cell detached from the cell wall
why is turgor important in plants?
plays an important role in maintaining the shape of soft tissues in plants. (example changes in turgor of the guard cells causes the opening and closing of stomata)
