cell membrane Flashcards
(18 cards)
what is the cell membrane?
● barrier between cell and environment
● partial permeable
● organelle membrane divides cell into components
● phospholipid bilayer - ‘fluid mosaic’
how many nanometers is the cell membrane?
7nm
why is the cell membrane described as a ‘fluid mosaic’?
● fluid: molecules able to move around within membrane
● mosaic: variety of different molecules
what are the parts of the cell membrane? (5)
● phospholipid
● channel proteins
● carrier proteins
● receptor
● enzymes
what does extracellular mean?
outside cell
what does intracellular mean?
inside cell
what are the types of extracellular receptors?
● glycolipid
● glycoprotein
fatty acid tails are…
● hydrophobic
● non polar
phosphates are…
● hydrophilic
● polar
what do small, charged, water soluble ions pass through and what process do they do this by?
● channel proteins
● by facilitated diffusion
what do small, uncharged, lipid soluble atoms pass through and what process do they do this by?
● phospholipids
● simple diffusion (passive)
what do large molecules (e.g. glucose / amino acids) pass through and what process do they do this by?
● carrier proteins
● by facilitated diffusion
what do carrier proteins do?
● molecules bind to it
● changes tertiary structure of carrier protein
what is facilitated diffusion?
● where it needs protein for help
● rate can be limited by number of proteins
how do you increase uptake?
need more carrier and channel proteins
what do enzymes do?
● hydrolyses bonds between molecules
● e.g. dipeptides into amino acids
what does active transport require?
● ATP
● requires lots of mitochondria
