7.2 and 7.3 Flashcards
(24 cards)
movement of a substance down its concentration gradient
diffusion
substances crossing the cell membrane down their concentration gradients
passive transport
small, nonpolar molecules passing directly through the lipid bilayer
simple diffusion
transport proteins helping ions and polar molecules go through cell
facilitated diffusion
types of passive transport
diffusion
simple diffusion
facilitated diffusion
osmosis
process of water diffusing across the cell membrane
osmosis
basic structure of a biological membrane, composed of 2 layers of phospholipids
lipid bilayer
a lipid that contains phosphorus and that is a structural component in cell membranes
phospholipid
the arrangement of phospholipids in the lipid bilayer
allows only certain substances to pass through
selectively permeable
semipermeable
solution with high concentration of solute compared to cell
hypertonic
solution with low concentration of solute compared to cell
hypotonic
concentrations of solute and water in solution are equal to those in the cell
isotonic
movement of water in:
hypertonic
hypotonic
isotonic
out of cell - shrinks
into cell - swells and may burst
back and forth - same size
to move a substance against its concentration gradient
active transport
requires energy
active transport
uses carrier proteins
active transport
passive transport
low to high concentration
active transport
high to low concentration
passive transport
moves products into, out of, or within cell
vesicles
a cell uses vesicles to move materials into the cell
endocytosis
a cell uses vesicles to move materials out of the cell
exocytosis
functions of proteins in cellular membranes
transports substances
identifies cells
detects surroundings
when the concentration of a substance is the same throughout a space
equilibrium
Parts of phospholipid molecule
hydrophilic head - phosphate head - polar - outside
hydrophobic tail - fatty acid tail - nonpolar - inside
