Lipids: Simple, Compound and Derived,Simple Lipids,CHOH,CH2OH,CH2OH,HO C R,O,HO C R,O,HO C R,O,CH,CH2,CH2,O C R,O,O C R,O,O C R,O,+ 3H2O,glycerol fatty acids,triacyl glycerol,Ester bond,R = long hydrocarbon chain,Fatty Acids,Saturated Fatty Acids possess only single bonds in their hydrocarbon chain. Unsaturated Fatty Acids have one or more double bond in the hydrocarbon chain.,Triglycerides,Animal sources Contain saturated fatty acids Solid at room temperature Fats Plant sources Contain unsaturated fatty acids Liquid at room temperature Oils,Triglycerides,Act as energy store Release twice as much energy per gram as proteins or carbohydrates Insoluble, stored as droplets in cytoplasm Stored in adipose tissue of mammals Also protect and insulate and provide buoyancy,Compound Lipids,O,CH2,CH2,C,R2,O,O,O,P,O,O,C,R1,O,O,R3,CH,R1 = fatty acid R2 = fatty acid R3 = polar group,(phospholipid),Phosphoglyceride,Phospholipid,Hydrophilic “head” - polar group Hydrophobic “tail” - 2 fatty acid chains Molecule with hydrophilic and hydrophobic portions - Amphipathic Simplest has phosphate group only Most have alcohols esterified to phosphate group,Alcohol Groups,HO CH2 C H,COO-,NH3+,serine,HO CH2 CH2 NH3+,ethanolamine,HO CH2 CH2 N+ (CH3)3,choline,Sphingolipids,H,H,H,H3C (CH2)12 C = C C C CH2OH,H,OH,NH2,to 1 fatty acid,to phosphate,Sphingolipids have sphingosine backbone instead of glycerol,sphingosine,Sphingomyelin,H,H,OH,R C = O,CH3,CH3,H,H,N - H,O,O-,R = fatty acid,choline,H3C (CH2)12 C = C C C CH2 O P O CH2 CH2 N+ CH3,Fatty acid chain bonded to sphingosine molecule via an amide bond not ester bond,Glycolipids,H,H,OH,R C = O,H,H,N H,R = fatty acid,H3C (CH2)12 C = C C C CH2 O - Galactose,Galactocerebroside,Derived Lipids,Steroids,Four rings of carbon atoms Designated A, B, C, D Synthesised from cholesterol Cholesterol precursor for steroid hormones,Cholesterol,A,B,C,D,HO,O,O,O,HO,HO,OH,O,O,HO,HO,Cortisol,Corticosterone,Progesterone,O,Plasma Membrane,Made up of lipid bilayer and proteins Lipid bilayer - double layer of lipid hydrophilic heads to outside hydrophobic tails to inside Proteins integral - within bilayer peripheral - on surface of bilayer Fluid structure - Fluid Mosaic Model,Polar head (hydrophilic),Fatty acid tail (hydrophobic),glycolipid,Integral proteins,Peripheral proteins,cholesterol,Lipid bilayer,Function of Plasma Membrane,Lipid Bilayer Barrier to entry and exit of charged or polar substances (glucose) Freely permeable to water, O2 and CO2 Glycolipids act as cell markers Protein Act as transporters and channels for polar molecules Receptors for binding of molecules Cell Markers,