cell membrane transport Flashcards
two ways that substances can be moved across a membrane
PASSIVE transport and ACTIVE transport
what form of cell membrane transport requires energy
active
passive transport is chill and doesn’t care, no energy
diffusion:
the movement of PARTICLES from a region of HIGH concentration to a region of LOW concentration
the difference in concentration between two regions:
concentration gradient
in diffusion, particles move ___ their concentration gradient
down/along
osmosis:
the diffusion of WATER from an area of HIGH concentration to LOW concentration
WHAT from the extra cellular fluid and from the inside of the cell diffuses freely through the cell membrane.
water
the direction of osmosis depends on:
the concentration of water molecules on either side of the cell membrane
isotonic solution
equal movement of water into and out of cells (ideal for ANIMALS)
hypertonic solution (PLASMOLYSIS)
less water, more solute
WATER FLOWS OUT, CELL SHRIVELS
ideal for plants
hypotonic solution (LYSIS)
more water, less solute
WATER MOVES INSIDE, CELL BURSTS
facilitated diffusion:
cell membrane is filled with proteins that act as CHANNELS/CARRIERS that help in the passive transport of molecules into or out of cell
facilitated diffusion needs ___ to make way across
PROTEIN
channel proteins form a:
passageway for substances
when channel protein passageway opens, it can transport:
CHARGED PARTICLES or SMALL POLAR MOLECULES across cell membrane
a charged particle can only pass through the channel if:
it has the right charge
a positively charged channel can only transport a negatively charged ion