Chapter 3.2 Flashcards
active mechanisms that require cell energy
active transport, endocytosis, exocytosis, transcytosis
passive mechanisms that do not require cell energy
simple diffusion, facilitated diffusion, osmosis, filtration
ability of osmosis to generate enough pressure to move a volume of water
osmotic pressure
osmotic pressure increases as…
the concentration of nonpermeable solutes increases
same osmotic pressure
isotonic
higher osmotic pressure (water loss)
hypertonic
lower osmotic pressure (water gain)
hypotonic
another passive process of moving material through a cell
membrane
filtration
type of gradient diffusion and osmosis rely on
concentration gradient
type of gradient diffusion filtration uses
pressure gradient
movement in filtration
molecules will move from an area of higher pressure
to an area of lower pressure. Filtration is non-specific.
the movement of dissolved molecules into or out of a cell through the cell membrane, from a region of lower concentration to a region of higher concentration.
active transport
cell engulfs a substance by forming a vesicle around the
substance
endocytosis
three types of endocytosis
pinocytosis (mostly water) , phagocytosis (mostly solid), receptor-mediated endocytosis
- substances in a vesicle fuse with
cell membrane - contents released outside the
cell - release of neurotransmitters
from nerve cells
exocytosis