cell transport Flashcards
passive transport
no energy required
types of passive transport
- diffusion
- facilitated diffusion
- osmosis
active transport
energy required
uses a carrier protein
types of active transport
- protein pumps
- endocytosis (phagocytosis and pinocytosis)
- exocytosis
random kinetic motion
brownian motion
concentration gradient
when there is a difference in concentration of particles in one area compared to an another
diffusion
- the movement of particles from an area of high concentration to an area of low concentration it will continue until dynamic equilibrium is reached
- this doesn’ t require energy
dynamic equilibrium
dynamic implies movment
equilibrium implies a balance
sooo dynamic equilibrium means there is no net movement
osmosis
the diffusion of water across a selectively permeable membrane from an area of high concentration to low concentration and no energy required
solution
a homogeneous mixture composed of two or more substances
solute
is a substance dissolved in an another substance
solvent
the “another” substance
ex. salt water : the salt is the solute and the water is the solvent
hypertonic
concentration of dissolved substance is higher outside the cell than inside the cell
the cell shrinks and dies - water moves out
hypotonic
concetration of dissolved substances is lower outside the cell than inside
cell expands, may burst - water moves in
isotonic
solute concentration of solution equal to that of the cell
normal size cell - no net water movement
turgor pressure
pressure from the water in the vacoules pushing against the cell membrane and against the cell wall of a plant cell this keeps the plants stiff and it happens in a hypotonic solution
plasmolysis
process in which cells lose water in hypertonic solution
5 main affects of diffusion
temperature, charge, diameter (size), concentration gradient, surface area of membrane
affects of diffusion: temperature
high temp makes diffusion go faster
affects of diffusion : charge
charged molecules can’t pass throught the membrane without help
affects of diffusion: diameter (size)
large molecules can’t fit across the membrane without help
affects of diffusion: concentration gradient
the steeper the gradient is the faster diffusion is
affects of diffusion: surface area of membrane
the higher the surface area the more places diffusion can occur
facilitated diffusion
diffusion but with the help of transport proteins/ carrier proteins (channel proteins)
no enrgy required
gate has to be opened or a specific binding site
