Molecular Orbitals and Period 2 Diatomic | Ch 9 - 79E

BIOL 160 Sphack Transport Across Membrane Important point key term learning objective Plasma Membranes - Selective permeability o Allows compounds inside that cell needs o Keeps band compouds out - allows cell to maintain homeostasis o environment inside cell can be different from outside of cell - allows compartmentalization o chemical reactions are more efficient o reactions that don’t go well together can be separated Fluid Mosaic Model – a model that shows how proteins are imbedded in the membrane - model includes phospholipids and proteins o integral proteins – inside the hydrophobic bilayer  amphipathic – part hydrophilic and part hydrophobic  can span a membrane  can have segments facing the inside and outside of cell o peripheral proteins - on the outsides of the bilayer/hydrophilic sides  found only on the side of the membrane  peripheral proteins are usually attached to integral proteins - proteins in general can be amphipathic o the hydrophilic amino acids will be towards the end o hydrophobic amino acids will stay in the middle Freeze Fracture proteins – experiment that figured out proteins were imbedded in the membrane - scientist froze a cell in ice - broke off a section of the ice