PHYSIOEX Lab 1 - Experiments 1-5 Flashcards
What is it called when the plasma membrane allows it to be selective about what passes through it?
selectively permeable
selectively permeable allows ____________ and appropriate amounts of ______ to enter the cell and keeps out ________________
nutrients, ions, undesireable substances
transport through the plasma membrane occurs in two basic ways
passively and actively
describe passive process
the transport process is driven by ceoncentration or pressure differences between the interior and exterior fo the cell
describe active process:
the cell provides energy ATP to power the transport
two key passive processes of membrane transport are:
diffusion and filtration
this diffusion occurs without the assistance of membrane proteins
Simple diffusion
Facilitated diffusion requires _____________ that assists in the transport
membrane bound carrier protein
T/F: In both simple and facilitated diffusion: the substance being transported moves with the concentration gradient of the solute
True
Does simple and facilitated diffusion require energy from the cell?
No
where does filtration only occur in?
across the capillary walls
what does filtration depend upon?
pressure gradient
what are the two key active processes?
active transport and vesicular transport
describe active transport
uses a membrane-bound carrier protein
differs from facilitated because the solutes move AGAINST their concentration gradient
ATP is used to power the transport
describe vesicular transport
includes: phagocytosis endocytosis pinocytosis exocytosis
define concentration gradient
the net effect of this random molecular movement is that the molecules eventually become evenly distributed throughout the environment
define diffusion:
the movement of molecules from a region of their higher concentration to a region of their lower concentration
Q: driving force of diffusion is
kinetic energy of the molecules in motion
Q: in diffusion, molecules move
from a higher concentration to a region of their lower
Q: which of the following dialysis membranes has the largest pore size
200 MWCO
Q: Avogadro’s number is a constant for the number of
molecules
what does Facilitated Diffusion allow to pass through?
allows sugars, amino acides, ions to transport through the membranes by a passive transport
what would cause a molecule to not be able to pass through the pores in the cell plasma membrane?
lipid insoluble or too large to pass through
what do solutes combine with in the membrane to be allowed to be transported with their concetration gradient
carrier protein molecules
in facilitated diffusion, molecules might change _______ to accommodate solute
shape
T/F: carrier proteins are embedded in the plasma membrane and act like a shield, protecting the hydrophillic solute from the lipid portions of the membranes
TRUE
Filtration occurs in _______ direction for a given solute
one
__________ the concentration difference between one side of the membrane and the other, the __________ the rate of facilitated diffusion
greater, greater
Q: molecules need a carrier protein to help them move across a membrane because they are
lipid insoluble or they are too large
Q: which of the following is true of facilitated diffusion
movement is passive and down a concetration gradient
Q: examples of solutes that might require facilitated diffusion
glucose, sodium, potassium
Q: which of the following would not affect the rate of facilitated diffusion
the amount of intracellular ATP
define osmosis
water rmoves with its concentraton gradient from a higher concentration of water to a lower concentration of water.
a membrane is called ______, ______. or _____ if it allows some solute particles to pass but not others
selectively permeable
differentially permeable
semipermeable
the concentration of water in a solution depends on what?
the number of solute particles present.
Increasing/Decreasing the solute concentration coincides with decreasing/increasing the water concetration
increasing / decreasing
define osmotic pressure
the force that would need to be applied to oppose the osmosis in a closed system
osmotic pressure is measured in
millimeters of mercury
the more impermeable the solutes, the ______ the osmotic pressure
higher
define tonicity
refers to the way a solution affects the folume of a cell
T/F: the tonicity of a solution tells us whether or not a cell will shrink or swell
TRUE
define isotonic
when the concetration of impermeable solutes is the same inside and outside the cell
define hypertonic
if there is a higher concetration of impermeable solutes outside the cell than in the cell’s interior
the net movement of water would be ____ of the cell, the cell would _____ in a hypertonic solution
out of the cell
shrink
define hypotonic
the concentration of impermeable solutes is lower outside of the cell than in the cell’s anteior
in hypotonic: the net movement of water would be ______ the cell, and the cell would _______ and possibly _______
into the cell
swell and possibly burst
Q: which of the following is true of osmosis
it is a type of diffusion
Q: which of the followin goccurs when a hypertonic solution is added to the cell
cell shrinks
Q: the variable that affects osmotic pressure is
the concentration of non diffusing solutions
Q: the net movement of water would be into the cell in a
hypotonic solution
Define filtration
the process by which water and solutes pass through a membrane from an area of higher hydrostatic pressure into the area of lower hydrostatic pressure
filtration is a ________ process
passive
define filtrate:
the fluids and solutes that pass through the membrane
the amount of filtrate depends almost entirely on the _____________ and on the _____ of the membrane pores
pressure gradient and size of the membrane pores
solutes that are too large to pass through are retained by what? and include usually what/
capillaries
blod cells and proteins
what does MWCO stand for?
molecular weight cutoff. thin of this in erms of pore size.
the ______ the MWCo number, the _____ the pores in the filtration membrane
larger/larger
Q: filtration is the process that is
passive
filtration is dependent upon a
hydrostatic pressure gradient
Q: the filtrate includes:
fluids, solutes, passes through the filter
Q: an important place that filtration takes place in the body is
kidneys
define active transport
whenever a cell uses cellular energy (ATP) to move substances across its membrane
if substances are generally unable to pass by diffuse it is because:
- it might be too large to pass through the membrane pores
- it might not be a lipid soluble
- it might have to move agaisnt rather than with, a concetration gradient
Describe solute pumps
substances that are moved into the cells by solute pumps include amino acid and some sugars.
- both of the solutes are necessary for the life of the cell but they are lipid insolutble and too large to pass through membrane pores
sodium ions are ______ from the cells by _______
ejected
active transport
More Na+ _______ the cell than ______ the cell, makes Na_ to remain in the cell unless actively transported out
outside the cell than inside the cell
in the body, what is the most common type of solute pump
Na+-K pump
T/F: Na+-K pump, moves Na+ and K+ in opposite directions across cellular membranes and require energy
TRUE
____ Na+ ions are ejected from the cell for every ____ K- ions entering the cell
3, 2
membrane carrier proteins that move more than one substance, such as the Na+-K+ pump, participate in
coupled transport
if the solutes move in the same direction, the carrier is a
symporter
if the solutes move in opporsite direction, the carrier is an
antiporter
a carrier that transports on a single solute is a
uniporter
Q: the movement of sodium and potassium maintained by the Na+-K pump:
requires energy and is against a concentration gradient
Q: the sodium-potassium pump is classified as a
antiporter
Q: the sodium-potassum pump moves
3 sodium ions and 2 potassium ions simultaneously
Q: solutes that require active transport for movement might be too large to pass or might be a
lipid insoluble
which of the following would not affect the rate of facilitated diffusion
the amount of intracellular ATP
the variable that affects osmotic pressure is
the concentration of non diffusing solutes
