Biological Membranes Flashcards
Fluid mosaic model
Theory of cell membrane structure with proteins embedded in the sea of phospholipids
Glycolipid
Lipid/phospholipid with a chain of carbohydrate molecules attached
Glycoprotein
Protein with a chain of carbohydrate molecules attached
Plasma membrane
Cell surface membrane
osmosis
water moves from high water potential to low water potential down a water potential gradient through a partially permeable membrane
features of osmosis
the more concentration, the more solute so the more water molecules tied therefore, there are less water molecules free to take part in osmosis passive process (requires no energy) partially permeable water potential gradient equilibrium
hypotonic solution
a dilute solution with not many solutes
hypertonic solution
concentrated solution with many solutes
isotonic solution
equal concentration of solutes and water
cytolysis
in animal cells, if a lot water molecules enter, the cell will swell and burst as the plasma membrane breaks
turgid
in plant cells, the rigid and strong cellulose wall will prevent bursting. the cell will swell up to a certain size when its contents push against the cell wall which will resist any further swelling. turgidity of plant cells help support plants especially those that aren’t woody
crenated
when animal cells shrivel
plasmolysed
when the cytoplasm of plant cells shrink and the membrane pulls away from the cellulose wall, they suffer a degree of dehydration and their metabolism can’t proceed as enzyme-catalysed reactions need to be in solution
flaccid
plant tissue with plasmolysed cells
diffusion
movement of molecules from an area of high concentration of that molecule to an area of low concentration (may/may not be across a membrane, doesn’t need ATP)