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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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BiologicallyImportantMoleculesIntroductionWehavealreadyseeninourstudyofbiochemistrythatthemoleculesthatcompriselivingthingsarecarbon-based,andthattheyarethoughttohaveoriginatedfrominorganicmolecules.Itisthoughtthatinlivingorganisms,thereareover10,000compoundsthatexisttohelptheorganismfunctionThesecompoundsbelongtofourmajorgroupsofbiologicallyimportantmoleculesthatperformfourmajorfunctionsinlivingthings:

● Energystorage● Cellularstructure● Cellularregulationandcommunication● Informationstorageandtransfer

Butwhatdothesemoleculeshaveincommon?Aretheredetectablepatternsthatexistamonggroupsofmoleculesinlivingorganisms?Howarethesemoleculesassembled?We’llexploretheanswerstothosequestionsinthisactivity.

FindingPatternsinBiologicallyImportantMoleculesThemoleculesthatmakelifepossiblearebuiltoffofcarbonbackbones,whichactasscaffoldsfortheotheratomsfoundinorganicmolecules--namelyhydrogen,oxygen,nitrogen,phosphorusandsulfur.Buttheseatomsarenotusuallyfoundassoloatomsbranchedoffofthecarbonbackbones.Theyaremostoftenfoundasgroupsofatomsknownasfunctionalgroups.Thesefunctionalgroupsareclustersofatomsfoundtogetherthatprovidemoleculeswithcertainchemicalproperties,suchaspolarityoracidity.Themostimportantfunctionalgroupsfoundinbiologicallyimportantmoleculesareshowninthechartsbelow.

FunctionalGroups:Thesearethemostcommonfunctionalgroupsfoundinthefourclassesofbiologicallyimportantmoleculeswe’llbeexploring.DIRECTIONS:First,cutapartthemoleculecardsyouhavebeengiven.Thereare42differentbiomoleculesonthesecards.Next,identifyandmarkthefunctionalgroupsyouseeonthemoleculecardsinthefollowingway:● Hydroxylgroups:circleinred● Aldehydes&Ketones:triangleinorange● Carboxylgroup:boxthegroupingreen● Aminogroup:triangleinyellow● Phosphategroup:circleinpurple● Sulfhydrylgroup:boxthegroupinblue

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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Noworganizethemoleculecardsintogroupsbasedonsimilaritiesintheirstructure.Whengroupingthemolecules,paycloseattentiontothefollowing:

● Thefunctionalgroupsthatarepresent● Theshapeofthemolecule● AnypatternsyouseewithinthemoleculeNowlet’slookatthefourmajorgroupsofbiologicallyimportantmolecules:● Carbohydrates● Lipids(includessteroidsandfattyacids)● NucleicAcids● AminoAcids

GROUP1:CarbohydratesMonosaccharides(simplesugars)arethebuildingblocksofcarbohydrates.Theyareliterallyhydratesofcarbon,havingthegeneralformulaCn(H2O)n.Sugarsareburned(oxidized)toreleaseenergyincellularrespirationandtheyplayanimportantroleinhomeostasis.Yourbodymaintainsthelevelofthesugarglucoseinyourbloodwithinaverynarrowrange.Glucoseistheimmediatesourceofenergyforyourcells.Sugarsoccurasringstructures.Therearemonosaccharides(foundassinglerings),disaccharides(foundasdoublerings),andpolysaccharides(3+rings).Wheninaqueoussolution,sugarsfoundassingleringscandynamicallychangefromstraightchainstoringsandbacktostraightchains.Thesamesugarmoleculeshowninringandstraightchainformisshownbelow.Noticethateverycarbonhasanoxygenattachedtoit.

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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Itshouldalsobenotedthatglucosecanbefoundasanisomer.Anisomerisacompoundthathasthesamechemicalformulabutadifferentphysicalstructure.Alsonoticethatthecarbonatomsarenumberedinthemoeculesabove.Thiswillbecomeimportantwhenwelearnaboutnucleicacidstructureandfunction.

Sugarscanbejoinedtogetherinlongchainstoformmacromoleculescalledpolysaccharides.Starch,cellulose,andglycogenareexamplesofpolysaccharides.Starch(inplants)andglycogen(inanimals)areeasilybrokendownintosugarsforenergy.Cellulose,ontheotherhand,whichismadeinplants,canbebrokendownonlybyafeworganismsintheworld(primarilythebacteriainthegutsoftermitesandherbivorousanimalssuchascowsandsheep).Yetallthreetypesofmacromoleculesaremadeoflongchainsofsugar,andcellulosediffersonlybyasmallchangeintheconnectingbondbetweeneachpairofsugars.

DIRECTIONS:1. InyourBILL,createtheheading“Monosaccharides.”2. Underneaththeheading,pastethe8monosaccharidemoleculecardstothepage.3. Finally,createtheheading“Disaccharides”andpastethetwodisaccharidesugarsintoyourBILLunder

thisheading.

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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GROUP2:LipidsThereareseveraltypesoflipidsmadeandusedbylivingorganisms,including:

● triglyceridefats,phospholipids&steroidsLipidsareadiversegroupofmoleculesbutalltypesoflipidsshareoneimportantcharacteristic:theyareallhydrophobicandarethusinsolubleinwater.Likecarbohydrates,theyarecomposedofcarbon,hydrogenandoxygenbuttheratiosofeachatomdifferfromthatofcarbohydrates.Thefirstgroupoflipidswe’llexamineisthetriglyceridefats,composedofglycerolandfattyacids.Inyoursetofmoleculecards,youshouldhavesomelonghydrocarbonchainswithacarboxylgroupatoneend.Oneofthedefiningfeaturesofthesehydrocarbonchainsistheabsenceofoxygenexceptinonecarboxylgroupatoneendofthemolecule.Thesehydrocarbonchainsarefattyacids.Alongwithasmall3-carbonmoleculecalledglycerol,fattyacidsarethebuildingblocksofoilsandfats.Therearetwotypesoffattyacidstructuresyoushouldfamiliarizeyourselfwith:saturatedandunsaturated.Thesecondgroupoflipidswe’llexamineisthesteroids.Steroidsareatypeoflipidformedoffourcarbonringsfusedtogether.Lookingatthediagramofcholesterolshownatright,you’reprobablythinking,“Butthere’snocarbonintherings!”Itshouldbenotedthatorganicchemistsuseshortcutswhenrepresentingcomplexstructuresoforganicmolecules,sowhatyouareseeingatrightisaskeletalformulaforcholesterol.Becauseorganicmoleculesincludesomanycarbonatoms,chemistsoftendonotincludetheletterCforcarbon.Inthecholesterolmoleculeabove,thereisacarbonatom(notdrawninmostcases)ateverypointofeachofthefourringsandinthesidechain.Thebondsbetweenthecarbonsareshown.Inallbutonecasethecarbonatomsareconnectedtooneanotherbyasinglebond(onepairofsharedelectrons).Inoneringtherearetwocarbonatomsconnectedbyadoublebond(whichmeanstheyaresharingtwoelectrons).Tofurthersimplifythisdrawing,manyofthehydrogenatomshavenotbeendrawn.However,sinceeachcarbonatomformsfourbonds,itisassumedthatthebondsnotdepictedaretohydrogenatoms.Cholesterolservestwoimportantrolesincells:itisamajorcomponentofcellmembranes,anditalsoservesasthebuildingblockforthehormonestestosterone,cortisolandestrogen.

DIRECTIONS:1. InyourBILL,createtheheading“ExampleLipids:TriglycerideFats”andpastethe4componentsof

triglyceridefatsunderneath.Youshouldalsopastethetwoexamplesoftriglyceridefatshereaswell.2. Identifyeachfattyacidandtriglyceridefataseithersaturatedorunsaturated.3. Next,createtheheading“ExampleLipids:Steroids”andpastethe3steroidmoleculesunderneath.

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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GROUP3:NucleicAcidsNucleicacidsincludetwokindsofmolecules,RNA(ribonucleicacid)andDNA(deoxyribonucleicacid),andtheirmonomers,nucleotides.Inmostorganisms,DNAcontainsthegeneticblueprintfortheorganismandisreproducedinitsentiretyinnearlyeverycellofitsbody.RNAhelpstotranslatetheinformationinDNAintotheproductionofthousandsofdifferentkindsofproteins,whichinturncontroldevelopmentoftheorganism.Auniquecharacteristicofthenucleicacidsisthepresenceofanitrogenousbase.Thenitrogenousbasesconsistofsingleordoublerings.Eachringcontainstwonitrogenatoms.DNAcontainsfournitrogenousbases:adenine(A)andguanine(G),eachwithdoublerings,andcytosine(C),andthymine(T),withsinglerings.RNAcontainsthreeofthese,A,G,andC,andafourthbase,uracil(U).Thenitrogenousbasesfoundinnucleicacidsareonlyonecomponentofthemonomersofnucleicacids.Themonomerofnucleicacidsiscalledanucleotideandiscomposedof3things:anitrogenbase,a5-carbonsugar,andaphosphategroup.Thesugarsfoundinnucleotidesaremonosaccharidesugarsknownaspentoses,becausetheyonlyhave5carbonsarrangedinaringshape.

Whenanitrogenousbaseisattachedtoa5-carbonsugar,itisknownasanucleoside.

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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Nucleosidescancombinewithone,twoorthreephosphatestoformanucleotide.Thegreaterthenumberofphosphates,thegreatertheenergycontainedinthemolecule.Cyclicadenosinemonophosphate(cAMP),derivedfromATP,isusedasasecondmessengermoleculeinsomecellularsignalingpathways.Adenosinediphosphate(ADP)isanintermediatemoleculethatisphosphorylated(hasaphosphategroupattached)inmanymetabolicpathwaysandisusedtotransferenergybetweenmoleculesinorderforcellstoperformwork.Adeninetriphosphate(ATP)isnotonlyamajorsubunitofDNAandRNA,butalsoisamajorenergycarrierinlivingsystems.Youcanseethatithasanitrogenousbase(adenine),a5-carbonsugar(ribose)andthreephosphategroups.

DIRECTIONS:1. Createtheheading“NitrogenousBases”andpastethe5nitrogenousbasemoleculecardsunderneath.2. Identifyeachaseitherapurineorapyrimidineandlabelthemappropriately.3. Createtheheading“Nucleosides”andpastethe4nucleosidemoleculecardsunderneath.Labelthesugarof

eachaseitherriboseordeoxyribose.4. Createtheheading“Nucleotides”andpastethe3nucleotidemoleculecardsunderneath.Labelthesugarof

eachaseitherriboseordeoxyribose.

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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GROUP4:AminoAcidsAminoacidsarethemonomersofproteins,biologicallyimportantmoleculesthatperformamultitudeoffunctionsinorganisms,including:

structuralproteins defense(asinantibodies) transportofmolecules hormones

enzymes receptorproteins contractileproteins storageofaminoacids

Thereare20differentaminoacidsfoundinlivingorganisms,andbecauseofthislargenumberofmonomers,itispossibletohaveanearlyinfinitenumberofpossibleproteinsthatcanbeformed.Proteinsequenceandstructureareencodedforbynucleicacids.TheinformationforthesequenceofeveryproteinyourcellsmakeisfoundintheDNA,andtheRNAinyourcellsisresponsibleforcarryingthatinformationtotheribosomesinthecytoplasm,whereassemblyofaminoacidsintoproteinsoccurs.Thestructureofageneralizedaminoacidisshownatright.Theaminogroupisfoundontheleftsideofthecentralcarbon(alsocalledalphacarbon),andthecarboxylgroupisfoundontherightsideofthecentralcarbon.NotethattheRgroupisvariable--thisiswhythereare20differentaminoacidsinlivingthings.

Whentwoaminoacidsarejoinedtogetherthroughtheprocessofdehydrationsynthesis(awatermoleculeisremovedbyjoiningtwomonomerstogether),theresultingmoleculeiscalledadipeptide:

Finally,whenmultipleaminoacidsarejoinedtogetherbypeptidebondsformedasaresultofdehydrationsynthesis,theresultingmoleculeisknownasapolypeptide.NotethattheN--C--Cbackboneisthehallmarkofproteinmolecules:

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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DIRECTIONS:1. InyourBILL,createtheheading“GeneralizedAminoAcid”anddrawthestructureforanaminoacid.Label

theaminogroup,carboxylgroup,centralcarbonandRgroup.2. Nowcreatetheheading“AminoAcids”andpastethe9aminoacidmoleculecardsunderneath.Highlightthe

atomsthatcomprisethebackboneofeachaminoacid.

WhatYouWillTurnIn:TheDeliverableEachstudentwillturninthefollowing:

● Acompletesetofcorrectlyidentifiedandlabeledmoleculecutouts○ Thisincludeslabelingthefunctionalgroupsandmoleculetype

● Acompletedbiomoleculessummarychart● Areflectionoflearning(writtenusingcompletesentences)thatincludesthefollowing:

○ 3thingsyoulearnedaboutbiomoleculestructure○ 2thingsyoulearnedaboutthesimilarityamongthebiologicallyimportantmolecules○ 1thingyoulearnedaboutbiologicallyimportantmoleculesthatyoudidnotknowbeforeparticipatingin

thisactivity

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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MoleculeCut-Outs:Usethesetocompletetheactivity.

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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AP Biology: Unit 1: Matter Pod 2: Molecules of Life

Adapted from activities by Kim Foglia and Jennifer Sosnowski by Lee Ferguson, Allen HS

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