evidence for fluid mosaic?

• first model? 3 layer protein sandwich.

  bad as didn't allow heads to be in contact with water or amino acids on outside to be kept away from water.

  • research into lipid bilayer formation used to refine model
• freeze fracture?

  smooth mosaic like surface seen and dispersed is molecules like proteins/lipids.

  • used molecule lectin labelled with ferritin which is visible under electron microscope, only binds to polysaccharides, lectin only bound to outside of membrane so outside is different from inside
• fusing of human/mouse cells?

  mouse cell labelled w/ green pigment for protein, humans labelled w red pigment for protein.

  • 2 cells allowed to fuse, immediately after fusing proteins stayed in respective places but after 40 mins 37 degrees. complete mix of protein.
  • could've only mixed via diffusion through surface so membranes are fluid.