Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

BIOL 201


Movement of molecules from 1 location to another b/c of random thermal molecular motion; always occurs from a region of high concentration to low. Diffusion
Irregular motion of small particles suspended in a liquid or a gas Brownian motion
the amount of molecules crossing a surface in a unit of time Flux
difference between two one-way fluxes Net flux
state during which diffusion fluxes in opposite directions are equal; that is, the net flux equals zero Diffusion equilibrium
4 factors that affect the rate of diffusion: temperature, mass of the molecule, surface area , and the medium or permeability coefficient
number that defines the proportionality between a flux and a concentration gradient and depends on the properties of the membrane and the diffusing molecule Permeability coefficient
Give examples of "non-polar molecules" that are able to diffuse through lipid bilayers Non-polar molecules: oxygen, carbon dioxide, urea, fatty acids, steroids
small passage in plasma membrane through which certain small diameter molecules and ions can diffuse Channel
voltage difference between inside and outside of a cell Membrane potential
Name the most common ions that diffuse through channels and their normal direction with relation to cells. Na, Cl, & Ca all "drive" into the cell, Na having the "highest net flux". K always "drives" out of the cell.
the driving force across a plasma membrane that dictates whether an ion will move into or out of a cell; established by both concentration and electrical charge differences...Concentration has Greater effect than electrical pull. Electrochemical gradient
the process of opening or closing ion channels Channel gating; (3) different types: chemically, mechanically, & voltage gated.
chemical messenger molecule binds to protein channel and can open or close the channel (ligand) or Chemically gated channel
membrane ion channel that is opened or closed by deformation or stretch of the plasma membrane Mechanically gated channel
membrane ion channel opened or closed by changes in membrane potential (voltage) Voltage gaged channel
movement of molecules across membrane by binding to protein transporter; includes facilitated and active transport Mediated transport
integral membrane protein that mediates passage of molecule through membrane; also called carrier Transporter
system that uses a transporter coupled to an energy source to move ions or molecules across a membrane against an electrochemical difference; "uphill" Active transport
system using a transporter to move molecules "downhill" from high to low concentration; no energy required Facilitated transport
active transport in which chemical energy is transferred directly from ATP to transporter protein Primary Active Transport
during the movement of an ion along its normal electrochemical gradient(concentration & energy)it is coupled to the transport of another molecule which is moving "uphill" against its concentration. Secondary Active Transport
Most common ex: of primary active transport is the movement of Na & K ions across plasma membranes by Na+/K+ ATPase pumps Na+/K+ ATPase pumps: For each ATP hydrolyzed, 3 Na ions pump out of a cell & 2 K ions pump in.
KNOW Standard values of Na & K levels inside and outside of cells Intracellular fluid: Na= 15mM, K= 150mM; Extracellular fluid: Na= 150mM, K= 5mM
form of secondary active transport in which net movement of actively transported substance and molecule supplying the energy are in the same direction Cotransport
form of secondary active transport in which net movement of actively transported substance is in the opposite direction of the molecule supplying the energy Countertransport
net diffusion of water from region of higher water concentration (lower solute concentration) to region of lower water concentration (higher solute concentration) Osmosis
total solute concentration of a solution; what is the "normal" physiological level? Osmolarity; 300mOsm
one mole of solute ions and molecules Osmol; 1 Osm
membrane permeable to some substances (usually water) but not to others (some solutes) Semipermeable membrane
pressure that must be applied to a solution on one side of a membrane to prevent the net flow of water across the membrane. Force should always be = & opposite of Hydrostatic Pressure Osmotic pressure
dissolved substance that does not passively diffuse across a plasma membrane Non-penetrating solute
any solution that does not cause the change in cell size; has the same concentration of non-penetrating solutes as normal extracellular fluid Isotonic
solutions that have a non-penetrating solute concentration lower than that found in cells, therefore water moves by osmosis into the cells, causing them to swell Hypotonic (hypo= big, cells swell)
solutions containing > than 300 mOsm of non-penetrating solutes, cause cells to shrink as water diffuses out of the cell into the fluid with the lower water concentration Hypertonic
having the same total solute concentration as extracellular fluid Isoosmotic
having total solute concentration less than that of normal (300mOsm)extracellular fluid Hypoosmotic
having total solute concentration greater than normal extracellular fluid> 300mOsm Hyperosmotic
process in which intracellular vesicle fuses with plasma membrane, & its contents are released (exit) into the extracellular fluid Exocytosis
process in which plasma membrane folds into the cell, forming small pockets, membrane-bound vesicles, that "take in" particles from extracellular fluid Endocytosis
type of "fluid" endocytosis in which vesicles "drink" small amounts of extracellular fluid Pinocytosis
type of endocytosis in which vesicles "eat" large amounts of extracellular fluid Phagocytosis
type of endocytosis when certain molecules in the extracellular fluid bind to specific proteins (receptors) on the outer surface of the plasma membrane, the molecules are specifically taken in for cellular function or structure Receptor-mediated endocytosis
the space between adjacent cells of an epithelium through which some molecules diffuse as they cross the epithelium Paracellular pathway
crossing an epithelium by movement into an epithelial cell, diffusion through the cytosol of that cel, and exit across the opposite membrane Transcellular pathway(more complicated)
group of epithelial cells that secrete into the extracellular space hormones that then diffuse into the bloodstream Endocrine gland
cluster of epithelial cells cells specialized for secretion and having ducts that lead to an epithelial surface Exocrine gland
cluster of epithelial cells cells specialized for secretion and having ducts that lead to an epithelial surface
Created by: jhanson79



Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards