Slide 1Lipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsLipid Structures, Properties, and FunctionsPage 1LIPID STRUCTURES, PROPERTIES, and FUNCTIONSLehninger Readings Chapter 10 pages 357-370 and Chapter 21 pages 845-847, 874At the end of this section you should be able to use lipid nomenclature to discuss lipid structure and function, identify the function of a lipid based on its structure, predict how changes in lipid structure will alter its function in biological systems, and design an experiment to analyze a mixture of lipids.You should be able to: 1) Define lipids and compare lipids to other types of biomolecules.2) Describe the structural features found in common biological fatty acids and relate these to the properties and general functions of fatty acids. 3) Correctly use fatty acid nomenclature, draw the structures of palmitate, stearate, oleate, linoleate, ALA, arachidonate, EPA, and DHA and interconvert between the structure, the carbon skeleton shorthand, and the systematic name for common fatty acids. 4) Predict the physical and chemical properties of a fatty acid when given its structure. 5) Identify the components found in lipids and classify lipids according to their basic structures and functions.6) Compare and contrast the structural, physical, and chemical properties of the various lipids and relate these to their biological functions.7) Predict the functions of lipids based on their physical and chemical properties. 8) Recognize the structures of common membrane lipid head groups and relate these structures to the properties and functions of the head groups.9) Recognize examples of lipids produced from isoprene and describe some important cellular functions of these lipids. 10) Identify the bonds in lipids that are cleaved by various lipases and describe the biological importance of lipases. 11) Discuss examples of signaling carried out by lipids, the sources of these signal molecules, and the role of NSAIDs in disrupting signaling.12) Design an experiment to separate a mixture of lipids and identify the components of the lipids.Page 2Lipid Structures, Properties, and FunctionsFigure 1-7•Lipids–Definition•The cellular components that are soluble in organic solvents (chloroform, methanol) but sparingly soluble or insoluble in water.–General Properties•Very diverse structure, chemistry, and functions.•Hydrophobic or amphipathic.•Often contain fatty acids, sterols, or isoprene.–Functions•Energy storage.•Membranes.•Cofactors.•Electron carriers.•Hormones and other signal molecules.1) Define lipids and compare lipids to other types of biomolecules.–Nomenclature•Common Names•Shorthand carbon skeletons–Chain length:# double bonds ( bond position from -COOH end)∆•Systematic names•Omega () fatty acidsPage 3Lipid Structures, Properties, and Functions•Fatty Acids–General Structure•A carboxcylic acid head with a hydrocarbon tail•Saturated contain no double bonds in the hydrocarbon tail.•Monounsaturated contain a single double bond in the hydrocarbon tail, usually at C9 – almost always cis.•Polyunsaturated have double bonds separated by a methylene group (not conjugated) - almost always cis.•# of Carbon Atoms = 4 to 36– common biological fatty acids range from 12 to 24 fatty acids with an even number of carbon atoms–Properties•Determined by length and saturation.•Poorly soluble in water.•Melting point increases with length and degree of saturation.•Double bonds cause kinks the prevent packing – lowering the melting point.•Wedge shape causes micell formation.–Functions•Usually part of larger molecules via ester or amide bond. Figure 10-2Figure 10-2Figure 11-4see also Figure 2-72) Describe the structural features found in common biological fatty acids and relate these to the properties and general functions of fatty acids. 3) Correctly use fatty acid nomenclature, draw the structures of palmitate, stearate, oleate, linoleate, ALA, arachidonate, EPA, and DHA and interconvert between the structure, the carbon skeleton shorthand, and the systematic name for common fatty acids.Page 4Lipid Structures, Properties, and Functions4) Predict the physical and chemical properties of a fatty acid when given its structure. Figure 10-75) Identify the components found in lipids and classify lipids according to their basic structures and functions.6) Compare and contrast the structural, physical, and chemical properties of the various lipids and relate these to their biological functions.7) Predict the functions of lipids based on their physical and chemical properties. SterolsPage 5Lipid Structures, Properties, and Functions•Triacylglycerols –Structure•A glycerol backbone with three fatty acids attached by ester linkages. •The fatty acids can be the same but are most often different. –Properties•Most abundant lipids in the human body but DO NOT form membranes.•Hydrophobic - stored in anhydrous form.•Lighter than water. •F.A.s attached determine properties (liquid or solid at RT)–Functions•Primarily metabolic storage molecules (fats in animals, oils in plants). –More reduced carbon provides more energy than carbohydrates.–Glycogen stores last 24 hrs -TAG stores last 2-3 months!•InsulationFigure 10-3Figure 10-7Page 6Lipid Structures, Properties, and Functions•Membrane Lipids –General Structure•Amphipathic–Polar head group»Phosphodiester»Sugar–Hydrophobic portion »Fatty acids »Isoprene derivative•Very diverse due to mixing and matching of head groups and tails•Backbones–Glycerol–Sphingosine–General Properties•Membrane lipids are amphipathic.•Due to cylindrical cross section they form bilayers and liposomes in aqueous solutions.–Polar heads exposed to aqueous solution.–Hydrophobic tails buried.Figure 10-7Figure 11-4SterolsPage 7Lipid Structures, Properties, and Functions•Membrane Lipids –Classes•Glycerophospholipids–Structure»glycerol backbone »FA’s esterified to C1 and C2 »head group attached to C3 by a phosphodiester