SubstanceswithapHbelow7arecalledAcids.SubstanceswithapHabove7arecalledBases.SubstanceswithapHof7areNeutral.Wateristheonlyneutralsubstance.
ThepHscaleactuallymeasurestheamountofHYDROGENIONS(H+)thatarepresentinasolution.pHcouldstandfor“THEPOWEROFHYDROGEN.”ThelowerthepHvalue,thegreatertheamountofhydrogenions(H+)presentinthesolution
YouCANPassYourBiologySOL!S
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Step1:MakeanOBSERVATION.Thetwotypesare: →QUALITATIVE:Descriptions withoutnumber.(Ex)The bookisheavy. →QUANITATIVE:Descriptions thatusenumbers.(Ex)The bookhas250pages.Step2:MakeaHYPOTHESIS.Thisisaneducatedguessbasedonqualitativeandquantitativedata.⇒Scientistshouldlookfor2variablesintryingtofindanswerstotheproblem. ◊INDEPENDENTVARIABLE(IV) ThethingIchange ◊DEPENDENTVARIABLE(DV) ThethingImeasure
Step3:SetupaCONTROLLEDEXPERIMENT.Eachhas:
1. CONTROLGROUP:thegroupthatstaysthesame(doesn’treceivetheIV).It’sneededtocompare.
2. EXPERIMENTALGROUP:thegroupthatismanipulated(thegroupyouareperformingtheexperimenton).ThisgroupreceivestheIV.
Step4:MakeaCONCLUSIONorTHEORY
⇒ Ifthedatagatheredfromyourcontrolledexperimentsupportyourhypothesis,youacceptyourconclusion.⇒Ifthedatadoesn’tsupportyourhypothesis,startover!
HowtoIdentifyVariablesonaGraph:
*****ScientistsusetheSCIENTIFICMETHODtohelpthemanswerquestionsandsolveproblemsaboutthenaturalworld.*****
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YaxisistheDV.
ThethingIm
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XaxisistheIV.ThethingIchange
*Watermakeslifepossible!It’sauniversalsolvent,comesinthreestates,andhasahighspecificheattoregulatetemperature*ThechemicalformulaofwaterisH2O.Ithas2hydrogenand1oxygen.Waterhasapositiveside(hydrogen)andanegativeside(oxygen).Thesechargesallowwatertosticktootherthingsthatalsohaveacharge.HYDROGENBONDSholdwatertoitselfandtootherchargedsubstances.
Whenwaterstickstootherthings(likeacarwindow)ADHESIONistakingplace.WhenwaterstickstoitselfCOHESIONistakingplace
Watercomesin3states:solid,liquidorgas.Inthesolidstate(ice),waterislessdensethantheliquidstate.Icefloats!WaterhasaHIGHSPECIFICHEAT.Itcanabsorbalotofenergywithoutincreasingitsowntemperature.Thisiswhywatertakessolongtoboil!
Weusethispropertytohelpusregulateourbodytemperature.Whenourbodytemperaturegetstoohigh,westarttoPERSPIRE(sweat).
Wedonotwantourbodytemperaturetofluctuateverymuchbecauseitwouldalterchemicalreactions(METABOLISM).Whenmetabolismisthrownoff,HOMEOSTASIS(balance)isalsothrownoff.Thiscanleadtodeath!!!!
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*Alllivingthingsarecomposedof4macromolecules.Macromoleculesarelargepolymers(theprefix“poly”means“many”)thatarecomposedoflotsofsmallerbuildingblockscalledmonomers(theprefix“mono”means“one”).*
1. Carbohydrates:Theonly
macromoleculethatisusedforENERGY.CarbohydrateisafancywordforSUGAR.ThemostimportantsugarisGLUCOSE(C6H12O6).ThebuildingblocksofcarbohydratesareMONOSACCHARIDES.
2. Lipids:TheonlymacromoleculeusedtoSTOREENERGYandtoprovideINSULATION.Therearethreeclassesoflipids(fats,oils&waxes).ThebuildingblocksoflipidsareFATTYACIDS.
3. Proteins:TheonlymacromoleculethatcanSPEEDUPCHEMICALREACTIONSandprovideSTRUCTURE&SUPPORT.ThebuildingblocksofproteinsareAMINOACIDS.
4. NucleicAcids:TheonlymacromoleculesthatTRANSMITSHEREDITYINFORMATION.Therearetwotypesofnucleicacids:DNA&RNA.TheirbuildingblocksareNUCLEOTIDES.
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Enzyme
EnzymesareCATALYSTS.CatalystsSPEEDthingsup!Withoutenzymes,chemicalreactions(metabolism)wouldhappentooslowlytokeepyoualive.Enzymesareshapespecific.Enzymescanonlycatalyzereactants(Substrates)iftheycanfitinsidetheenzyme’sACTIVESITE.EnzymesspeedupchemicalreactionsbyLOWERINGACTIVATIONENERGY.Activationenergyistheamountofenergyneededtostartachemicalreaction.ActivationEnergyworkslikeaspeedbump.
• Thebiggertheactivationenergytheslowerthechemicalreaction
• Thesmallertheactivationenergythefasterthechemicalreaction.
*Enzymesarebiologicalcatalysts.Theyspeedupchemicalreactionsandregulatemetabolism.Enzymesareproteinsthatcanlowerachemicalreaction’sactivationenergy*
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Mic
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*Themicroscopeisoneofthemostimportanttoolsinbiology.Itallowedscientiststodiscoverthecellandallofitsstructures.*
Oncethemicroscopewasinvented,ROBERTHOOKEwasabletoseeandnamethetinystructuresthatmakeuplifewhilestudyingcork.HewasthefirstpersontousethewordCELL.
……………………………….………..…… Microscopes&theCellTheareonly2thingsthatyouneedto
knowaboutmicroscopes:
1. DeterminingTotalMagnification:Multiplytheeyepiece(thatisalways10x)bytheobjectivelens(thelensesthatcanberotated)
10xObjectiveLens=TotalMag.
2. MakingaWetMountSlide:Alwaysplacethecoversliponata45° Angletopreventairbubbles.
WiththehelpofHookeandotherscientistsworkingwiththemicroscope,theCELLTHEORYwascreated.THECELLTHEORY:
1. Alllivingthingsarecomposedofcells.
2. Cellsarethebasicunitsof
structureandfunctionoflife.
3. Cellscanonlycomefrompre‐existingcells. …
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Alllivingthingsaremadeupofonlyoneoftwotypeofcells:PROKARYOTICCELLSorEUKARYOTICCELLS.
• Prokaryotesaresimple,small,andlackanucleus.TheonlyexampleofaprokaryoteisBACTERIA.
• Eukaryotesarecomplex,large,andcontainanucleusandlotsoforganelles.Allprotists,fungji,plantsandanimalsaremadeupofeukaryoticcells.
****Everythinglivingthingsismadeupofatleastonecell.Cellsarethelowestlevelofstructureoflivingthingsthatcanstillperformalltheactivities(metabolism).****
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CellofEukaryotes
PlantCell AnimalCell
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****Eukaryotescontainmembrane‐boundORGANELLES.Eachorganelleperformsaspecificjobinthecelltohelpmaintainmetabolismandhomeostasis.****
1. NUCLEUS:Thisisthecontrolcenterofthecell.Itcontainsthecell’sDNAandcontrolsthecell’smetabolismandhomeostasis.
2. MITOCHONDRIA:Thisisthepowerplantofthecell.Thecell’senergysupply(ATP)ismadehereviaCELLULARRESPIRATION.
3. RIBOSOMES:Thesearethesitesofproteinsynthesisforthecell.
4. GOLGIAPPARATUS:Thisisthepostofficeofthecell.Itpackagesandexportsmaterialsinandaroundthecell.
5. ENDOPLASMICRETICULUM:Therearetwokinds:smoothandrough.Bothhelptomovethingsaroundthecell.Theyworklikeasystemofroadsinthecell.
6. LYSOSOMES:Thesearethegarbagecansofthecell.Theybreakdownwaste.
7. CHLOROPLAST:Thisisfoundinplantsandisthesiteofphotosynthesis.
8. CELLWALL:Thisisarigidlayerfoundontheoutsideofplantcells.Itgivesplantcellstheiruniquerectangularshape.
9. CELLMEMBRANE:Thissurroundsallcells.Itmaintainshomeostasisbycontrollingwhatcanenterandleavethecell. It’scomposedoftwolayersofPHOSPHOLIPIDS. ThePHOSPHOLIPIDBILAYERhasapolarheadandtwo
non‐polartails.Thisallowsthingsthataresmallandnonpolartocrossthemembranewithoutaskingforpermission.
Foodandrawmaterialsforchemicalreactionsmustbeabletocrossthemembrane.
Wastemustbeabletoleavethemembrane.
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****Substancesneedtobeabletotravelintoandoutofcellacrossthecellmembrane.Thismovementcaneitherhappen
spontaneously(byitself)orwiththeinputofenergy(ATP)****Therearetwotypesoftransport:PASSIVE&ACTIVE
1. PASSIVETRANSPORT:Thismovessubstancesacrossmembranesfromregionsofhighconcentrationtolowconcentrationwithoutenergy.
2. ACTIVETRANSPORT:Thismovessubstancesacrossmembranesfromregionsoflowconcentrationtohighconcentrationwithenergy(ATP) Examples:Endocytosis&
Exocytosis
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Thereare3typesofPASSIVETransport:
1. DIFFUSION:themovementofsubstancesfromaregionofhighconcentrationtolowconcentration.
2. OSMOSIS:themovementofwaterfromaregionofhighconcentrationtolowconcentration.
3. FACILITATEDDIFFISION:themovementofsubstancesfromhightolowwiththehelpofatransportprotein.
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****CELLULARRESPIRATIONandPHOTOSYNTHESISareprocessesthatallowcellstouseandmakeenergytokeepthecellalive.Theyhaveacyclicalrelationshipwithoneanother.Theydependononeanother!****
CellularRespiration Photosynthesis
CELLULARRESPIRATIONisaprocessthatturnssugar(glucoseC6H12O6)intousableenergyforthecell(ATP).HETEROTROPHS(organismswhocannotmaketheirownfood)usethisprocesstoreleaseATPfromfoodintheMITOCHONDRIA.
INPUT(Reactants):Mitochondriatakeinoxygenandglucose
OUTPUTS(Products):MitochondriareleasecarbondioxideandATP!!!!
PHOTOSYNTHESISisaprocessthatturnslightenergyfromthesunintofood(glucose)forplants.PlantsandorganismsthatmaketheirownfoodarecalledAUTOTROPHS.AutotrophsperformphotosynthesisintheirCHLOROPLASTS.
INPUT(Reactants):Chloroplaststakeincarbondioxideandsunlight.
OUTPUTS(Products):Chloroplastsreleaseoxygenandglucose.
CO2 O2
Glucose
Chloroplast
Mitochondria
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****DNAisadouble‐helixcomposedof2complementarystrands.Ithas4nucleotidescomposedofeitherA,T,C,orG:ApairswithT,GpairswithC.ThisstructuremakesDNAREPLICATIONandPROTEINSYNTHESISpossible.!****
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WhenDNAneedstodivide,DNAREPLICATIONbegins.TheweakhydrogenbondsthatareholdingthetwostrandsofDNAtogetherbreakapartandtheDNA“unzips.”ThetwooriginalstrandsofDNAthenbecometemplatesfornewdaughterstrandsofDNAthatwillform.
ChromosomeStructure:
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****TheprocessofturningDNAintoproteinsfollowsaspecificorder.Itstartsinthenucleusandendsattheribosome.****Frst,DNAisturnedintoMESSENGERRNA(mRNA).RNAistheskinnycousinofDNAwhichmeansitcanleavethenucleus.RNAissingle‐stranded.ItonestrandlooksalmostidenticaltoDNAwiththeexceptionofthenitrogenbaseURACIL.Uraciltakestheplaceofthymine.,soUpairswithA.
♦ MakingRNAfromDNAiscalledTRANSCRIPTION.
Next,themessagetransferredfromDNAtomRNAmakesitwaytotheribosome(thesiteofproteinsynthesis).
♦ MakingproteinsfrommRNAiscalledTRANSLATION.
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****DNAisthecell’sgeneticmaterial.Itmustbecopiedbeforethecellcandivide.Tohelpwiththis,theDNAispackaging
intostructurescalledCHROMOSOMES.Humanshave46chromosomesthatmustbecopiedexactlybeforethecellcandivide.TheprocessofcelldivisioniscalledMITOSIS.Mitosishas4steps:PROPHASE,METAPHASE,ANAPHASE&TELOPHASE.****
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****GENETICSisthestudyofheredity.AGENEisabasicunitofheredity.AnALLELEisoneoftwoormorealternativeformsofaspecificgene.Twoallelesmakeupagene.GREGORMENDELcrossedpeastodevelopthegenetictheorywestilluse.****Therearetwotypesofalleles:
‐DOMINANTALLELES:Theexpressedtrait.Representedbyacapitalletter.
‐RECESSIVEALLELES:Theunexpressedtrait.Representedbyalowercaseletter.Thetwoletters(representingtwoalleles)representanorganism’sGENOTYPE.Therearetwotypesofgenotypes:
‐HOMOZYGOUS:twoidenticalalleles (TT)or(tt)‐HETEROZYGOUS:twodifferent alleles(Tt)
Theexpressionofthegenotype(physicalappearanceofthegene)isthePHENOTYPE.Wecanusetheparentgenotypestopredictwhatoffspringmightlooklike.MonohybridcrossescanbecompletedbyusingaPUNNETSQUARE.
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Exampleofamonohybridcross:Consideracrossbetweenatruebreedingtallplant(TT)andatruebreedingshortplant(tt).
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****Alloflifecanbeclassifiedinoneof6kingdoms.Eachkingdomcanbebrokendownintoevensmallerunitsforclassification.Themoderndayclassificationsystemisbasedonatwo‐wordnamingsystemcalledBINOMIAL
NOMENCLATURE.Thisnamingsysteminvolvesanorganism’sGENUSandSPECIES.****
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The6kingdomsofthelifeare:1. Archaebacteria:Prokaryoticorganismsthatareonly
foundinextremeenvironments.2. Eubacteria:Single‐celled,prokaryoticorganismsthat
cancausesickness(Example:streptococcus&salmonella)
3. Protist:Single‐celled,eukaryoticorganismsthatcanbeeitherheterotrophic(protozoa)orautotrophic(algae).
4. Fungi:Multicellulareukaryoticorganismswithcellwallscomposedofchitin.Theseorganismsareexternaldigesters(heterotrophic).
5. Plant:Multicellulareukaryoticautotrophswithcellwallscomposedofcellulose.
6. Animal:Multicellulareukaryicheterotrophsthatdonothavecellwalls.
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****EVOLUTIONistheprocessbywhichspecieschangeovertime.It’sbroughtonbytheprocessofNATURALSELECTION.Naturalselectionallowsforindividualswithcertaintraitstosuccessfullysurviveandreproduce,passingthosetraitstothe
nextgeneration.****SPECIATIONistheprocessbywhichnewspeciesarise. Therearetwomechanismsthatcan
leadtonewspecies:o GeographicIsolation:the
physicalseparationofspeciespopulationsbygeographicbarriers(Example:oceansandmountains)
o ReproductiveIsolation:IsolationWITHOUTthepresenceofaphysicalbarrier.(Example:Onegroupofindividualsonlymatesinthefall,andanotheronlyreproducesinthespring.) …
…………………………………………………… ASPECIESisagroupofindividualsthatcaninterbreedandproduce
fertileoffspring.‐Thehorseandzebraarebothmembersoftheirownspecies.Howdoweknow?Whenweforcethemtomate,theiroff‐spring(azebroid)isnotfertile.
EvidenceforEvolution****Scientistshave3areasoffocusthatprovideevidenceforevolution.****
1.Fossils 2.Anatomy 3.Biochemistry
Scientistscanuselayersofundisturbedrocktodeterminetherelativeageoffossilizedorganisms.TheOLDESTfossilswillalwaysbeatthebottomofthecolumnandtheYOUNGESTatthetop.
ThistechniqueiscalledthePRINCIPLEOFSUPERPOSITION.
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HOMOLOGOUSSTRUCTURES:StructuresthatlookSIMILARtooneanother.ThesedemonstratedescentfromaCOMMONANCESTOR(DivergentEvolution)ANALOGOUSSTRUCTURES:Differentstructuresthatperformsimilarfunctions.Theenvironmentforcesunrelatedindividualstodevelopstructurestoperformsimilarfunction.NOCOMMONANCESTOR!(ConvergentEvolution)
Remember:OrganismsthathavemoreDNAincommonarecloselyrelated!Thismeansthatorganismsthathavemoreproteinsincommonarealsocloselyrelated.Lookattheaminoacidchainofunknownanimal:MetGlySerTyrTyrArgHisHisGluLysItmostcloselyresembles?Horse:Met‐Gly‐Ser‐Ser‐Tyr‐Arg‐Arg‐Asp‐His‐GluDog:Met‐Gly‐Ser‐Tyr‐Tyr‐Arg‐His‐Asp‐Glu‐LysCat:Met‐Gly‐Ser‐Tyr‐Tyr‐Arg‐His‐His‐Arg‐CysMouse:Met‐Gly‐Ser‐Tyr‐Tyr‐Arg‐His‐Glu‐Val‐ValOurunknownanimalismostcloselyrelatedtothedog!There’sonly1differenceintheproteinsequence.
Met‐Gly‐Ser‐Tyr‐Tyr‐Arg‐His‐Asp‐Glu‐Lys ……………………………….………………………………