Cell Membrane Flashcards
plasma mem. fun.
governs interactions w/ o/ cells
controls flow of mat. in and out of cell
separates inside from the outside
phospholipid bilayer
2 hydrophobic tails (non-polar) and 1 hydrophilic head (polar)
mem. lipids
embedded in plasma mem.
sm amount mem. lipids
adds structure
lrg amnt mem. lipids
makes mem. more fluid
phosph. heads can’t connect and form bond
mem. proteins
*not common in mem.
make up 50% of mem. weight
move freely throughout mem. (like ice cube in water)
integral protein
penetrate mem.
transmem. protein
goes all the way through mem.
top and bottom hydrophilic
middle is hydrophobic to coincide w/ bilayer
peripheral proteins
DO NOT enter bilayer
stick to inter/extracellular face of mem.
protein receptor types
receptor cell adhesion mol enzyme channel protein gated channel protein cell id marker
receptor
binds chem. messages (hormones) from o/ cells
cell adhesion mol.
connects cells and allows them to stick to surroundings
used for tissue structure
enzyme
breaks down chem messenger (from receptor) + stops its effect
channel protein
path open all the time (LEAK)
lets solutes in and out
gated channel protein
allows solutes to pass @ specific times according to conce.
cell id marker
Ex. glycoprotein
distinguish own cells from foreign cells
types of channel protein
leak
stimuli response
stimuli response channel pro. types
ligand (chem mess)
voltage (electrical potential)
mechanically (physical stress)
glycocalyx
sugary coating on plasma mem.
determines own cells from transplanted ones
extensions from cell surface
microvilli
cilia
pseudopods
microvilli
inc cells SA (more area for absorption)
cilia (motile)
function in waves move mucus, egg cell or fluid
psedudopods
cytoplasm filled extension of cell
look like little amputated arm
membrane transports favors ?? polarity
hydrophobic -
non-polar
filtration
phys. pressure forces fluid through SPM
Diffusion
diffuse solutes down con. gradient
forms free energy
rate can be affected
osmosis
net flow of h20 one side of SPM to the o/
maintains body’s water distribution
flows from less solute con. to higher solute con.
aquarporins
channel that h2o flows through
osmotic pressure
need for h20
more non-perm. solute inc pressure
reverse osmosis
h2o against con. gradient w/ mechanical force
osmolarity
osmotic concentration of body fluids
tonicity
solute can affect vol. and pressure inside of cell
if sol. unevenly distributed
carrier-mediated transport
need mem! + ATP
protein changes shape to carry mol. across mem.
have specificity
contain saturation to a point
saturation point for carrier-mediated transport
transport maximum
Types of carriers
uniport
contransport
countertransport
uniport
carries 1 type of solute
contransport
2+ types of solute in same direction
countertransport
2+ types of solute in different directions
moves 2+ solute in same direction
symport
moves 2+ solute in opposite direction
antiport
CMT- Facilitated diffusion
solute through mem. down con. gradient
no ATP
CMT- Primary active transport
Need ATP
substance through mem. up con. gradient
Na-K Pump
3 Na out of cell
2 K in cell
secondary active transport
mvmnt of ions up and down con. grad.
one structure powers another
Ex. Na-K to Glucose
Vesicular Transport
move lrg particles through mem
h2o and fluid
Vesic. T- endocytosis
mol. in cell
consumed, broken down and deposited
Vesic. T- exocytosis
mol. out of cell
endocytosis types
phagocytosis
pinocytosis
receptor-mediated
phagocytosis
consumes bac, dirt and cell decay
pinocytosis
takes in ECF for cell
receptor-mediated
extracts mol. from ECF
selective
transcytosis
transports mol. by receptor-mediated
