Cell Membrane Flashcards
what is the function of lipoprotein cell membrane
provide support, cell recognition, separate cell contents from ecxternal envrionment
explain the fluid mosaic model
- membrane = semi permeable (selective exchange)
2. consists of phospolipid bilayer with many different protein molecules
what is diffusion
movement of substance from low concentration to high concentration
what are some factors affecting diffusion
size, charge, temperature, solubility
what is osmosis
diffusion of solvent from a low solute concentration towards high results in equal concentration on both side
what does isotonic mean (osmosis)
if a cell is places in solution of equal concentration = no change
what does hypertonic mean (osmosis)
if a cell is placed in solution with more concentration it will shrivel
what does hypotonic mean (osmosis)
if a cell is placed in solution of less concentration it will either swell with water or pop
what are two factors that affect selective exchange
size/charge of particle and lipid solubility
what is faciliated diffusion (channel protein)
create pore in membraine which ions+water can diffuse
what is faciliated diffusion (transport protein)
changes shape to carry large molecules through membrane
what is active transport and how do carrier proteins help out
ATP is used to move substance against gradient
carrier proteins - select certain substances to pass across
what is endocytosis (enter)
membrane engulfs large/highly polar particles that wouldn’t otherwise be able to enter cell
what is exoctyosis (exit)
secretion of unwanted materials via material packing in vessicles which fuse with membrane and release
what is phagocytosis
intake of solid particles, membrane surrounds and encloses particle to enter cell, enzymes break down solids
