鬻 响审 多 secretory vesicle (f)
Secretory vesicle
The molecular constituents of Membranes proteins polar lipids carbohydrates-glycoprotein/glycolipids Each type of membrane has characteristic lipids and proteins table 12-1 Major Components of Plasma Membranes in Various Organisms Components(% by weight) Protein Phospholipid Sterol Sterol type Other lipids Human myelin sheath 19 Cholesterol Galactolipids, plasmalogens Mouse liver 26 7 Sitosterol Galactolipids 7 4 Ergosterol Triacylglycerols, steryl esters Paramecium(ciliated protist) Stigmasterol E. coli 75 0
The Molecular Constituents of Membranes -proteins -polar lipids -carbohydrates-glycoprotein/glycolipids Each type of membrane has characteristic lipids and proteins
Plasma Inner mitochondrial Outer p 日 mitochondrial composition of Lysosomal hepatocyte membranes Nuclear Rough Er th er Gol 100 Percent membrane lipid Cholesterol Phosphatidylserine Sphingolipid Cardiolipin Phosphatidylcholine Phosphatidylinositol Minor lipids Phosphatidylethanolamine phosphatidylglycerol
Phosphatidylserine Phosphatidylinositol phosphatidylglycerol Lipid composition of hepatocyte membranes
Protein composition of membranes: cell dependent and specific--more diverse than lipids Rod cells-90% proteins are the light-absorbing glycoprotein rhodopsin Erthrocytes--20 major species plus dozens of minor ones, glycophorin is a glycoprotein in red blood cells (60% of mass are made of sugars) E.coli--hundreds of proteins including transporters and enzymes
Protein composition of membranes: cell dependent and specific—more diverse than lipids Rod cells—90% proteins are the light-absorbing glycoprotein rhodopsin Erthrocytes—20 major species plus dozens of minor ones, glycophorin is a glycoprotein in red blood cells (60% of mass are made of sugars) E.coli—hundreds of proteins including transporters and enzymes
The Supramolecular Architecture of Membranes impermeable to most polar or charged solutes permeable to nonpolar compounds 5-8 nm(50-80A)thick trilaminar
The Supramolecular Architecture of Membranes --impermeable to most polar or charged solutes --permeable to nonpolar compounds --5-8 nm (50-80A) thick --trilaminar