cell membrane Flashcards
main functions
-selective passage of material
-dividing cell into specialized regions
-site on enzymes controlled chemical rxn
-site of receptors for cell
3 properties of phospholipid bilayer
- semi-permeable
- individual molecules are not static: floating around
3.self assembling in water
where is phospholipids attached
to cytoskeleton
head and tail
head= made of phosphate group, hydrophillic
tail= hydrphobic, fatty acids chain
can ions go through phospholipids?
yes they are impereable
passive transport: diffusion
random movement of things
occurs from area of high concentration to area of low
rate of temperature depends on..
temp- becuase higher temp=faster molecules
concentration gradient (diffusion)
the ability to pass through the membrane
why is cholesterol important for phospholipids?
it prevents passage of water in
lets say material too big to pass through phospholipids- how do they get through
protein -FACILITATED DIFFUSION
osmosis
backwards or diffusion. from area of low to area of high
-water takes most volume
terms used to compare salt (ion) concentration of 2 salts
isotonic= equal salt concentratio
hypotonic= one salt concentration is lower than other
hypertonic= one is higher than other
water moves toward…
hypertonic solution
no net movement once..
isotonic
active transport
movement of material,
requires potential energy stored by the cell
4 forms of energy
heat
kenetic energy- one directiom
potential/ stored energy
light
what is energy released to form bonds used for?
change shape of protein
move molecules
create new bonds
atp
kind of like a rechargeble battery
acts as short term energy storage and transport unit
includes phosphate and will require energy
2 types of active transport by atp
- transport against concentration gradiant…
-energizing transport protein itself - transport of impearmeable substances -too big
endocytosis vs exocytosis
endo= bring things into cell
exo= moving things out of cell
this cuase whole membrane to fold
