A cells environment Flashcards
cells are surrounded by…
water
small molecules dissolved in the water (constantly moving)
how do molecules move in water?
the move around and spread appart as they colide
move from high to low concentration
the amount of solute mixed in a solvent
how many molecules are mixed into the water
concentration
no additional energy needed
passive transport
additional energy needed
active transport
does not require extra energy
used it move smaller molecules that move freely through diffusion across the membrane
high to low
passive transport
what are the three types of passive transport
diffusion
osmmosis
facilitated diffustion
equal amount of molecules inside and outside cell
the molecules will move into and out of cell in both directions to maintain equalibrium
equalibrium
when there is not the same amount of molecules inside and outside the cell, it creates a _________
concentration gradient
process where larger molecules are moved into and out of the cell through special protein channels in cell membrane
facilitated diffusion
uses proteins
used only for large molecules that can fit
facilitated diffusion
moves materials across a membrane against concentration gradient (low to high)
uses ATP
active transport
active transport examples
Carrier proteins
Exocytosis
Endocytosis
protein changes its shape to bind to molecule
moves molecule across membrane then returns to original shape
used to some small molecules from low to high
carrier proteins
moves molecules out of cell useing vesicles to carrier them out
exocytosis
