Tìm hiểu về Lipits

LIPIT1LIPIDSNot polymersComprised almost exclusively of C and HNonpolar bonds  no H-bondingGenerally interact poorly with waterHydrophobic2LIPIDSKey roles of lipidsEnergy storageInsulationMembrane componentsCell communication3LIPIDSMajor classes of lipidsFats and oilsPhospholipidsSteroids4LIPIDSFats and oils“Triacylglycerols” or “triglycerides”Not polymersAssembled from smaller molecules through condensation reactionsGlycerolThree fatty acids5LIPIDSFats and oilsFatty acids contain long carbon skeletonsGenerally 16 – 18 carbonsThese carbon skeletons may contain only single bonds“Saturated”These skeletons may contain double bonds“Unsaturated”“Polyunsaturated”Cause chain to bend6LIPIDSFats and oilsSaturated fatsPresent in fatty meats, dairy products, coconut oil, etc.Possess only single bonds in fatty acid tailsMolecules can pack together tightlySolid at room temperature7LIPIDSFats and oilsUnsaturated fats (oils)Present in most plant and fish oils, etc.Possess double bonds in fatty acid tailsMolecules cannot pack together as tightlyGenerally liquid at room temperature8LIPIDSPhospholipidsSimilar to fatsGlycerol2 fatty acidsPhosphate(Inositol, choline, etc.)AmphipathicHydrophilic regionHydrophobic region9LIPIDSPhospholipidsAggregate in water-rich environmentsMicellesPhospholipid bilayersKey components of cell membranesHydrophobic regions are “hidden” from waterHydrophilic regions are in contact with water10LIPIDSCholesterolSteroidAmphipathicMembrane antifreezePrevents membrane solidification at low temperaturesPrecursor for all steroid hormones11LIPIDSSteroid hormonesSynthesized from cholesterolInvolved in a variety of body functionse.g., Developmente.g., Reproductione.g., Salt regulatione.g., Sugar biosynthesise.g., Water regulationetc.12LIPIDS13REFERENCESCampbell, Neil A. and Reese, Jane B. Biology, 7th edition. Pearson Education, Inc. 2005.Campbell, Neil A., Reese, Jane B., Taylor, Martha R., and Simon, Eric J. Biology, Concepts and Connections, 5th edition. Pearson Education, Inc. 2006.Nester, Eugene W., Anderson, Denise G., Roberts, C. Evans Jr., and Nester, Martha T. Microbiology, A Human Perspective, 5th edition. McGraw-Hill Companies, Inc. 2007.Limson, Janice. 2002.