3-2. Principles of Molecular Movement Flashcards
What are the two major types of movement?
passive - no energy input needed - high > low
active - requires energy/ATP - low > high
What are the types of passive processes?
diffusion
osmosis
filtration
What are the types of active processes?
primary active transport
secondary active transport
vesicular transport
diffusion
passive movement of molecules from areas of high to low concentration
dynamic equilibrium
molecules have distributed themselves evenly in the available space, no longer “net movement”
simple diffusion
small electrically neutral molecule readily diffusive across bylayer (eg. O^2)
facilitated diffusion
large or lipid-insoluble molecules need help of integral proteins that function as channels or carriers (eg. glucose)
osmosis
diffusion of water across a membrane - water passes through, solutes are blocked
concentration gradient
water moving from high to low concentrations - affected by the amount of solutes dissolved on either side of the membrane
solutes ___ water towards them
“solutes suck”
as the solute concentration increase, the water concentration ___.
decreases
tonicity
ability of a solution to change shape/tone of cells by altering water volume
isotonic
the two solutions have equal concentrations of solutes; no net movement of water
hypotonic
the solution has less solutes (and more water)
hypertonic
the solution has more solutes (and less water)
Cell 1 is 30% salt, cell 2 is 10% salt. Cell 1 is ____ to cell 2. Water will move ___ to cell 1.
hypertonic; into
hemolysis
a red blood cell placed into a hypotonic environment, the cell will swell until its membrane ruptures
crenation
red blood cell placed into a hypertonic environment, the cell will shrivel
A human cell (.9% solutes) is placed into a beaker of distilled water (0% solutes). What happens?
hemolysis - water goes into the cell by osmosis, causing it to burst
A patient with an edema might be given a ___ IV to draw excess water out of the tissue.
hypertonic
A severly dehydrated patient may be given a ___ IV to help rehydrate tissues.
hypotonic
This form of transportation moves substances from low to high concentrations.
active transport
This form of transportation moves substances from high to low concentration.
passive transport
filtration
the process that forces water and solutes through a membrane wall by hydrostatic pressure; driving force is a pressure gradient
This form of transport moves water through a concentration gradient from high to low.
osmosis
This form of transport moves water and solutes through a pressure gradient from high to low
filtration
These two particles are held back during filtration
blood cells and plasma protein molecules
Filtration occurs through ___ walls.
capillary
primary active transport
an integral protein receives an energy boost from ATP that allows it to pump a specific solute across the membrane against the concentration gradient (from low to high)
sodium-potassium pump
simultaneously pumps Na+ out and K+ back in, used in primary active transport
Na+-K+ ATPase
enzyme carrier used with the sodium potassium pump during primary active transport
secondary active transport
aka “coupled transport”
coupled transport of two solutes across a membrane; energy supplied by an ion gradient created by primary active solute pump
vesicular transport
how large molecules move in and out of cells
What are the two types of vesicular transport?
endocytosis and exocytosis
exocytosis
process where large molecules are moved out of a cell; substance removed first enters a secretory vessical, migrates to plasma membrane, fuses with it and then ruptures
endocytosis
process where large molecules move into a cell; region of plasma membrane encloses particles near surface, then pinches off to form a vessical moving into cytoplasm
What are the two types of endocytosis?
phagocytosis (cell eating) and pinocytosis (cell drinking)
phagocytosis
cell eating
pinocytosis
cell drinking
