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Jaja

cell transport

the movement of materials across cell membranes

cell membrane

thin, flexible barrier around a cell; regulates what enters and leaves the cell

phospholipid bilayer

a double layer of phospholipids that makes up plasma and organelle membranes

semi-permeable

characteristic of a cell membrane which allows some molecules to pass through but not others

nonpolar molecules

can pass through the cell membrane

polar molecules & ions

cannot pass directly through the cell membrane

membrane proteins

embedded proteins that perform specific functions for the cell membrane

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

intracellular space

space inside the cell

extracellular space

space outside the cell

passive transport

the movement of substances across a cell membrane WITHOUT the use of ATP energy by the cell

active transport

the movement of materials through a cell membrane using ATP energy

diffusion

movement of molecules from an area of higher concentration to an area of lower concentration until a state of equilibrium is reached

equilibrium

when a space is filled evenly; a state of balance

concentration

the amount of a particular substance in a given volume

concentration gradient

a difference in the concentration of a substance across a distance; particles will move from an area of high concentration to an area of low concentration

facilitated diffusion

diffusion of molecules that requires the help of transport proteins

channel proteins

proteins that serve as tunnels through the lipid bilayer

carrier proteins

transport specific substances that fit in their binding site

osmosis

diffusion of water through a selectively permeable membrane

aquaporins

special channel proteins through which water enters and exits the cell

osmotic pressure

the force driven by differences in solute concentration that results in the net movement of water out of or into a cell

tonicity

the concentrations of solutes in a solution

solute

the substance that is dissolved

solvent

the substance in which the solute dissolves

hypotonic solution

Subject solute concentration is lower than the non-subject comparison

isotonic solution

solute concentrations in the cell is equal to the solution surrounding the cell

hypertonic solution

Subject solute concentration is higher than the non-subject area

cell lysis

animal cells swell and burst

turgid

plant cells become swollen

flaccid

plant cells become soft and wilt

plasmolyzed

plant cell in hypertonic solution - pulling away from cell wall

crenate

when an animal cell shrivels due to water loss in a hypertonic solution

sodium-potassium pump

a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell

bulk transport

the process by which large particles and macromolecules are transported through plasma membranes.

endocytosis

the movement of a large substance into a cell by a vesicle

exocytosis

the movement of a large substance out of a cell by a vesicle

pinocytosis

cell drinking

phagocytosis

cell eating

secretion

removal of a good substance

excretion

removal of a bad substance (waste)

hydrophobic

water fearing (lipid tails)

hydrophilic

water loving (phosphorus head)