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IntroductiontoMacromolecules
Macromoleculesareasetofmoleculesthatarefoundinlivingorganisms.Macromoleculesessentiallymean“bigmolecules”asthewordmacromeanslarge.Thefunctionsofthesemacromoleculesplayavitalroleinmaintainingabalancedinternalenvironment.
Ifyouweretolookatthenutritionlabelofwholemilk,whatmainitemsstickout?
Youmayhavenoticedthecalories,fat,cholesterol,carbohydratesandprotein.
Threeoftheabovelisteditemsareinfactmacromolecules.
Fatandcholesterolarebothinthecategoryoflipids,andbothcarbohydratesandproteinsarebothcategoriesofmacromolecules.
Macromoleculeshave4categories
1. Carbohydrates2. Lipids3. Proteins4. NucleicAcids
Macromoleculesarebasicallyalong-chainofrepeatingstructure.Thinkofitaslego-blocksthatcanbeputtogethertomakeonelargestructure.Thesinglebuildingblocksarecalled“monomers”,whilethecombinationofmanylegoblocksarecalledpolymers.
Let’sbeginbylookingatcarbohydrates:
Carbohydratesaremadeupofsugarmolecules.Therearemanykindsofsugarmolecules.Thesugarthatweeatiscalledsucrose.Thesugarfoundinmilkislactose,andthemainsugarmoleculethatisfoundinbothanimalandplantorganismsarecalledglucose.Noticetheyallhaveanendingof–ose.
Glucosehasthebasicchemicalstructureofthefollowing:
Thereare6carbonatoms,12hydrogenatomsand6oxygenatoms.ThisgivesthebasicchemicalformulaofC6H12O6.
Thenameusedincarbohydratesiscalledsaccharide.Ifthereisjustonesaccharide(sugarmolecule),itiscalledmonosaccharide.Iftherearetwo,disaccharide,threefortrisaccharide.Anysugarthathastwoormorecouldbecalledpolysaccharide.Polysaccharideismostlyusedifthesugarmoleculesarefoundinalongerchainandisnotusedfor2sugarsconnectedtoeachother.
Whenchainsofglucoseareformedbylinkingmanyglucosemoleculestogether,wegetsomethingcalledcellulose,inplants,orglycogen,inanimals.
Celluloseprovidesthestructureforplants(suchasstems,andleaves).
Glycogenontheotherhandisfoundinanimalsandisusedasenergystorage.Animalscanbreakdownthechainsofglucosetogetindividualglucosemoleculestousethemasenergy.
Starchisanotherformofpolysaccharideswhereglucosechainsarelinkedtogether.Thedifferencebetweenglycogen,starchandcelluloseisduetohowtheglucosemoleculesarelinkedtogetherinthechemicalposition.Butatthistime,wewillfocusonthepolysaccharidesinsteadofthechemicalcomposition.Starchisfoundinplantsandisusedforenergystorage.Potatoesarerichinstarchandwhenweeatpotatoes,wearebreakingdownthestarchintosingleglucosemolecules.
Disaccharides(twosugarmoleculeslinkedtogether)
Othermorecomplicatedsugarscanbeformedbylinkingglucosemoleculestogether.
Disaccharidessuchassucrose(thesugarthatgivesthesweettaste)isformedbyconnectingaglucosemoleculewithafructose,whileamaltosesugariswhentwoglucosemoleculescombinedtogether.Lastly,lactose(thesugarthatcanmakesomepeople’sstomachupset)iswhenagalactoseandaglucoseislinkedtogether.
Disaccharidesarenotpolymersinthesensethattheydonotlinktogethertoformlargemolecules.Disaccharidesaresimplytwosugarmoleculescombinedintoonetomakeanotherformofasugar.
Usethelistonthenextpagetoseethedifferencebetweeneachofthem.
Notice how the 3 different carbohydrate polymers are made from the same glucose molecule but linked together in a different orientation
Alistofmonosaccharides,disaccharidesandpolysaccharides:
Lipids
Lipidsareessentiallyfatsofthebody.Lipidshowever,arenotconsideredasapolymer(repeatingsinglestructure).Lipidsformmanyimportantmoleculesfoundinourbodiessuchashormones,cholesterolandphospholipids.Thebasicstructureofafatmoleculehasamoleculecalledglycerolcombinedwith3fattyacidchains.Thefattyacidchainsarelongchainsofcarbonandhydrogenatomslinkedtogether.Themainfunctionoflipidisenergystorage.Otherfunctionsincludesendingsignalsaroundthebodywithhormones.
Ifyoulookatthelabelontheright,youwillnoticethatthereis“SaturatedFat”andTransfat.Basically,fatmoleculecanbebrokendowninto3types:Saturated,unsaturatedandtransfat.
Saturatedfatiswhenthefattyacidchain(thelongchain)hasjustsinglebonds(SforsaturatedandSforsinglebonds)whileunsaturatedfathasdoublebondsbetweenthecarbonatoms.Thisdoesn’tseemveryimportantbutthebondingplaysanimportantrole.Byhavingjustsinglebonds,thefatmoleculescanactuallypackmore,andformamorecondensestructure.Animalfatismadeupofsaturatedfat.Unsaturatedfathasadoublebondinthefattyacidchain,soitwillnot“pack”asclosebecauseoftheconfigurationsoyourbodycanprocessiteasier.
Transfatisanothertypeoffatanditiswhatitisclassifiedas“badfat”.Transfatisformedbyanotherdoublebondbutinanotherconfiguration.
Notice the single double bond on the fatty acid chain can cause it to become an unsaturated fat
Proteins:
Proteinsareimportantmoleculesthatmakeupatleast50%ofdrycellmass.Thefunctionsofproteinsarestructure,signaling(sendingsignals),protection(defense),carryoutchemicalreactions,transport,movement,andstorage.Proteinsaremadeupofmanysinglemoleculescalledaminoacidsthatarelinkedtogethersimilartocarbohydrates.Thereare20aminoacidsthatmakeupproteinsandtheyarelinkedtogetherby“Peptidebond”.Peptidebondisalinkagethatconnectstwoaminoacidstogetherandcanbelinkedwith1000sofotheraminoacids.
20AminoAcids
The peptide bond links the amino acid molecules together
Nucleicacids
Nucleicacidsmakeupthegeneticmaterialoflivingorganisms.Itcanmakeupdeoxyribonucleicacids(DNA),orribonucleicacids(RNA).Thebasicstructureofnucleicacidsiscomposedofsimplelinkageofnucleotides.ThenucleotideslinktogetherinlongchainsformingRNAorDNA.Individualnucleotidesareformedby3components,aribose(5carbonsugar)+nitrogenousbase+phosphatemolecule.ThevariationsofRNAandDNAcomefromthenitrogenousbasesthatformthenucleotides.Therearefourdifferentkinds,adenine(A),cytosine(C),guanine(G),andthymine(T).InorderforDNAtoformadoublehelix,hydrogenbondslinkneighboringnitrogenousbasestogether.
DNA’sdoublehelixiswhenhydrogenbondsformbetweenadjacentnitrogenousbases.
Basic nucleotide structure with a sugar base, phosphate group and a nitrogenous base
DNA is attached together by hydrogen bond between the nitrogenous bases