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Cell Membrane (plasmalemma) components phospholipid bilayer similar to but missing polar group = triglycerides three fatty acids + glycerol storage of energy main constituent of fats and oil concise storage of energy have a polar group at head, fatty acids at tail interacts with water fatty acids repelled by water group together to form membranes in water on their own two fatty acids + Phosphor types (additions to phosphor = polar group) phosphatidylcholine choline added phosphatidylserine serine phosphatidylinositol inositol phosphatidylethanolamine ethanolamine bilayer two layers from grouped phopholipids fatty acids of each layer point to each other heads on one side in cell heads on other side outside cell other types of phospholipid uses something other than glyerol backbone sphingomyelins kinks in the faty acids allow for movement in membrane  2 types of fatty acids saturated unsaturated with a kink from double covalent bonds cholesterol used to add strength to membrane creates additional liquidity by creating more space between phospholipids only on exterior membranes plasma membrane layers exterior phosphatidylcholine + sphingomyelins interior phosphatidylserine + phosphatidylinositol + phosphatidylethanolamine internal packages (cytolemmas) for export have layers reversed around item to eject from cell membrane proteins integral penetrate membrane usually in alpha-helix form functions cell identity markers carriers used as transporters transport channels anchors cell adhesion molecules enzymes surface for chemical reactions peripheral sits on or in membrane attaches to either integral proteins or membrane determines what function cell will perform in its environment  cytoskeleton = network of internal membrane proteins Functions separate inside outside regulates movement of molecules in and out of cell maintains electrochemical gradient allows for action-potential / impulses cell to cell interaction Qualities semipermeable

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