chapter 2- movement of substances Flashcards
what is the definition of diffusion?
diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration down a concentration gradient until equilibrium is reached.
how does diffusion move?
through PPM
what is the role of diffusion?
allow the exchange of nutrients
what are the factors that affect the rate of diffusion?
temperature, concentration gradient, size of molecules and the diffusion distance.
how does temperature affect?
higher the temperature, the higher the rate of diffusion
how does concentration gradient affect?
the steeper concentration, the higher the rate of diffusion
how does the size of molecules affect?
the heavier the molecule, the lower the net movement; the lighter the molecule, the higher the net movement.
how does the diffusion distance affect?
the closer the diffusion distance, the higher the rate of diffusion (shorter amount of time taken)
the definition of osmosis
the net movement of water molecules from a region of higher water potential to a region of lower water potentials through a partially permeable membrane
is a dilute solution high WP or low WP
high WP
what are the effects of osmosis on a plant cell?
it can cause the plant cell to be turgid or be plasmolysed, depending on the WP between the solution and cell.
what are the effects of osmosis on animal cell?
it can cause the animal cell to be lysed (cytolysis) and crenated, depending on the WP between the solution and cell.
when will the plant cell be plasmolysed?
when the plant cell has a higher water potential compared to the solution it is in.
when will the plant cell be turgid?
when the plant cell has lower water potential compared to the solution it is in.
when will the animal cell be lysed?
when the animal cell has lower water potential compared to the solution it is in.
