YouCANPassYourBiologySOL! Scientific Method *****ScientistsusetheSCIENTIFICMETHODtohelpthemanswerquestionsandsolveproblemsaboutthenaturalworld.***** Step1:MakeanOBSERVATION.Thetwo typesare: QUALITATIVE:Descriptions withoutnumber.(ex)the bookisheavy. QUANITATIVE:Descriptions thatusenumbers.(ex)the bookhas250pages. Step2:MakeaHYPOTHESIS.Thisisan educatedguessbasedon qualitativeandquantitativedata. Scientistshouldlookfor2 variablesintryingtofind answerstotheproblem. INDEPENDENTVARIABLE(IV) ThethingIchange DEPENDENTVARIABLE(DV) ThethingImeasure. HowtoIdentifyVariableson agraph: Y axisisthedv. ThethingImeasure X axisistheiv. ThethingIchange. Step3:SetupaCONTROLLED EXPERIMENT.Eachhas: 1. CONTROLGROUP:thegroup thatstaysthesame(doesn t receivetheiv).it sneededto compare. 2. EXPERIMENTALGROUP:the groupthatismanipulated(the groupyouareperformingthe experimenton).thisgroup receivestheiv. Step4:MakeaCONCLUSIONorTHEORY Ifthedatagatheredfromyour controlledexperimentsupport yourhypothesis,youaccept yourconclusion. Ifthedatadoesn tsupport yourhypothesis,startover! Water & its Properties *Watermakeslifepossible!It sauniversalsolvent,comesinthreestates,andhasahighspecificheattoregulatetemperature* ThechemicalformulaofwaterisH2O.It has2hydrogenand1oxygen. Waterhasapositiveside(hydrogen)anda negativeside(oxygen).thesecharges allowwatertosticktootherthingsthat alsohaveacharge. HYDROGENBONDSholdwatertoitself andtootherchargedsubstances. Whenwaterstickstootherthings(likea carwindow)adhesionistakingplace. WhenwaterstickstoitselfCOHESIONis takingplace Watercomesin3states:solid,liquidor gas.inthesolidstate(ice),waterisless densethantheliquidstate.icefloats! WaterhasaHIGHSPECIFICHEAT.Itcan absorbalotofenergywithoutincreasing itsowntemperature.thisiswhywater takessolongtoboil! Weusethispropertytohelpus regulateourbodytemperature. Whenourbodytemperaturegets toohigh,westarttoperspire (sweat). Wedonotwantourbodytemperature tofluctuateverymuchbecauseit wouldalterchemicalreactions (METABOLISM).When metabolismisthrownoff, HOMEOSTASIS(balance)isalso thrownoff.thiscanleadtodeath!!!! ph Scale SubstanceswithapHbelow7arecalledAcids.SubstanceswithapHabove7arecalledBases.SubstanceswithapHof7areNeutral.Wateris theonlyneutralsubstance. ThepHscaleactuallymeasurestheamountofHYDROGENIONS(H+)thatarepresentinasolution.pHcouldstandfor THEPOWEROF HYDROGEN. ThelowerthepHvalue,thegreatertheamountofhydrogenions(H+)presentinthesolution
Macromolecules *Alllivingthingsarecomposedof4macromolecules.Macromoleculesarelargepolymers(theprefix poly means many ) thatarecomposedoflotsofsmallerbuildingblockscalledmonomers(theprefix mono means one ).* 1. Carbohydrates:Theonly macromoleculethatisusedfor ENERGY.Carbohydrateisafancy wordforsugar.themostimportant sugarisglucose(c6h12o6).the buildingblocksofcarbohydratesare MONOSACCHARIDES. 2. Lipids:Theonlymacromoleculeused tostoreenergyandtoprovide INSULATION.Therearethreeclasses oflipids(fats,oils&waxes).the buildingblocksoflipidsarefatty ACIDS. 3. Proteins:Theonlymacromolecule thatcanspeedupchemical REACTIONSandprovide STRUCTURE&SUPPORT.The buildingblocksofproteinsareamino ACIDS. 4. NucleicAcids:Theonly macromoleculesthattransmits HEREDITYINFORMATION.There aretwotypesofnucleicacids:dna& RNA.Theirbuildingblocksare NUCLEOTIDES.. Macromolecules Enzyme EnzymesareCATALYSTS.Catalysts SPEEDthingsup! Withoutenzymes,chemicalreactions (metabolism)wouldhappentooslowlyto keepyoualive. Enzymesareshapespecific.Enzymescan onlycatalyzereactants(substrates)if theycanfitinsidetheenzyme sactive SITE. Enzymesspeedupchemicalreactionsby LOWERINGACTIVATIONENERGY. Activationenergyistheamountofenergy neededtostartachemicalreaction. ActivationEnergyworkslikeaspeed bump. Thebiggertheactivationenergy theslowerthechemicalreaction Thesmallertheactivation energythefasterthechemical reaction. *Enzymesarebiologicalcatalysts.Theyspeedupchemicalreactionsandregulatemetabolism.Enzymesareproteinsthatcan lowerachemicalreaction sactivationenergy* Enzymes.
Microscopy *Themicroscopeisoneofthemostimportanttoolsinbiology.Itallowedscientiststodiscoverthecellandallofitsstructures.* Theareonly2thingsthatyouneedto knowaboutmicroscopes: 1. DeterminingTotal Magnification:Multiplythe eyepiece(thatisalways10x)by theobjectivelens(thelensesthat canberotated) 10xObjectiveLens=TotalMag. 2. MakingaWet MountSlide: Alwaysplacethecoversliponat a45 Angletopreventair bubbles.... Oncethemicroscopewasinvented, ROBERTHOOKEwasabletoseeand namethetinystructuresthatmakeuplife whilestudyingcork.hewasthefirst persontousethewordcell. Microscopes&theCell WiththehelpofHookeandother scientistsworkingwiththemicroscope, thecelltheorywascreated. THECELLTHEORY: 1. Alllivingthingsarecomposedof cells. 2. Cellsarethebasicunitsof structureandfunctionoflife. 3. Cellscanonlycomefrompre existingcells... Cells: An Overview Cell Structures Alllivingthingsaremadeupofonlyoneof twotypeofcells:prokaryoticcellsor EUKARYOTICCELLS. ****Everythinglivingthingsismadeupofatleastonecell.Cellsarethelowestlevelofstructureoflivingthingsthatcanstill performalltheactivities(metabolism).**** Prokaryotesaresimple,small, andlackanucleus.theonly exampleofaprokaryoteis BACTERIA. Eukaryotesarecomplex,large, andcontainanucleusandlotsof organelles.allprotists,fungji, plantsandanimalsaremadeup ofeukaryoticcells. Cell Structures..... PlantCell CellofEukaryotes AnimalCell ****Eukaryotescontainmembrane boundorganelles.eachorganelleperformsaspecificjobinthecelltohelpmaintain metabolismandhomeostasis.**** 1. NUCLEUS:Thisisthecontrolcenter ofthecell.itcontainsthecell sdna andcontrolsthecell smetabolismand homeostasis. 2. MITOCHONDRIA:Thisisthepower plantofthecell.thecell senergy supply(atp)ismadeherevia CELLULARRESPIRATION. 3. RIBOSOMES:Thesearethesitesof proteinsynthesisforthecell. 4. GOLGIAPPARATUS:Thisisthepost officeofthecell.itpackagesand exportsmaterialsinandaroundthe cell. 5. ENDOPLASMICRETICULUM:There aretwokinds:smoothandrough. Bothhelptomovethingsaroundthe cell.theyworklikeasystemofroads inthecell. 6. LYSOSOMES:Thesearethegarbage cansofthecell.theybreakdown waste. 7. CHLOROPLAST:Thisisfoundinplantsandisthesiteof photosynthesis. 8. CELLWALL:Thisisarigidlayerfoundontheoutsideofplant cells.itgivesplantcellstheiruniquerectangularshape. 9. CELLMEMBRANE:Thissurroundsallcells.Itmaintains homeostasisbycontrollingwhatcanenterandleavethecell. It scomposedoftwolayersofphospholipids. ThePHOSPHOLIPIDBILAYERhasapolarheadandtwo non polartails.thisallowsthingsthataresmalland non polartocrossthemembranewithoutaskingfor permission. Foodandrawmaterialsfor chemicalreactionsmustbe abletocrossthemembrane. Wastemustbeabletoleave themembrane.
Transport ****Substancesneedtobeabletotravelintoandoutofcellacrossthecellmembrane.Thismovementcaneitherhappen spontaneously(byitself)orwiththeinputofenergy(atp)**** Therearetwotypesoftransport:PASSIVE &ACTIVE 1. PASSIVETRANSPORT:This movessubstancesacross membranesfromregionsofhigh concentrationtolow concentrationwithoutenergy. 2. ACTIVETRANSPORT:This movessubstancesacross membranesfromregionsoflow concentrationtohigh concentrationwithenergy(atp) Examples:Endocytosis& Exocytosis.. Thereare3typesofPASSIVETransport: 1. DIFFUSION:themovementofsubstancesfromaregionofhighconcentrationto lowconcentration. 2. OSMOSIS:themovementofwaterfromaregionofhighconcentrationtolow concentration. 3. FACILITATEDDIFFISION:themovementofsubstancesfromhightolowwiththe helpofatransportprotein. Metabolism ****CELLULARRESPIRATIONandPHOTOSYNTHESISareprocessesthatallowcellstouseandmakeenergytokeepthecell alive.theyhaveacyclicalrelationshipwithoneanother.theydependononeanother!**** CellularRespiration Photosynthesis CELLULARRESPIRATIONisaprocess thatturnssugar(glucosec6h12o6)into usableenergyforthecell(atp). HETEROTROPHS(organismswhocannot maketheirownfood)usethisprocessto releaseatpfromfoodinthe MITOCHONDRIA. INPUT(Reactants):Mitochondria takeinoxygenandglucose OUTPUTS(Products):Mitochondria releasecarbondioxideandatp!!!! PHOTOSYNTHESISisaprocessthatturns lightenergyfromthesunintofood (glucose)forplants.plantsandorganisms thatmaketheirownfoodarecalled AUTOTROPHS.Autotrophsperform photosynthesisintheirchloroplasts. INPUT(Reactants):Chloroplasts takeincarbondioxideandsunlight. OUTPUTS(Products):Chloroplasts releaseoxygenandglucose. CO2 O2 Glucose Chloroplast Mitochondria DNA ****DNAisadouble helixcomposedof2complementarystrands.ithas4nucleotidescomposedofeithera,t,c,org:apairs witht,gpairswithc.thisstructuremakesdnareplicationandproteinsynthesispossible.!****.. WhenDNAneedstodivide,DNAREPLICATIONbegins.Theweakhydrogenbonds thatareholdingthetwostrandsofdnatogetherbreakapartandthedna unzips. ThetwooriginalstrandsofDNAthenbecometemplatesfornewdaughterstrandsof DNAthatwillform.
ChromosomeStructure: DNA (continued) ****TheprocessofturningDNAintoproteinsfollowsaspecificorder.Itstartsinthenucleusandendsattheribosome.**** Frst,DNAisturnedintoMESSENGERRNA (mrna).rnaistheskinnycousinofdna whichmeansitcanleavethenucleus.rna issingle stranded.itonestrandlooks almostidenticaltodnawiththeexception ofthenitrogenbaseuracil.uraciltakes theplaceofthymine.,soupairswitha. MakingRNAfromDNAiscalled TRANSCRIPTION. Next,themessagetransferredfromDNAto mrnamakesitwaytotheribosome(the siteofproteinsynthesis). MakingproteinsfrommRNAis calledtranslation. Cell Division ****DNAisthecell sgeneticmaterial.itmustbecopiedbeforethecellcandivide.tohelpwiththis,thednaispackaging intostructurescalledchromosomes.humanshave46chromosomesthatmustbecopiedexactlybeforethecellcandivide. TheprocessofcelldivisioniscalledMITOSIS.Mitosishas4steps:PROPHASE,METAPHASE,ANAPHASE&TELOPHASE.**** Genetics ****GENETICSisthestudyofheredity.AGENEisabasicunitofheredity.AnALLELEisoneoftwoormorealternativeforms ofaspecificgene.twoallelesmakeupagene.gregormendelcrossedpeastodevelopthegenetictheorywestilluse.**** Therearetwotypesofalleles: DOMINANTALLELES:Theexpressed trait.representedbyacapitalletter. RECESSIVEALLELES:Theunexpressed trait.representedbyalowercaseletter. Thetwoletters(representingtwoalleles) representanorganism sgenotype. Therearetwotypesofgenotypes: HOMOZYGOUS:twoidenticalalleles (TT)or(tt) HETEROZYGOUS:twodifferent alleles(tt) Theexpressionofthegenotype(physical appearanceofthegene)isthe PHENOTYPE. Wecanusetheparentgenotypesto predictwhatoffspringmightlooklike. Monohybridcrossescanbecompletedby usingapunnetsquare...... Exampleofamonohybridcross:Consideracrossbetweenatruebreedingtallplant (TT)andatruebreedingshortplant(tt).
Classification.. ****All of life can be classified in one of 6 kingdoms. Each kingdom can be broken down into even smaller units for classification. The modern day classification system is based on a two word naming system called BINOMIAL NOMENCLATURE. This naming system involves an organism s GENUS and SPECIES.**** The 6 kingdoms of the life are: 1. Archaebacteria: Prokaryotic organisms that are only found in extreme environments. 2. Eubacteria: Single celled, prokaryotic organisms that can cause sickness (Example: streptococcus & salmonella) 3. Protist: Single celled, eukaryotic organisms that can be either heterotrophic (protozoa) or autotrophic (algae). 4. Fungi: Multicellular eukaryotic organisms with cell walls composed of chitin. These organisms are external digesters (heterotrophic). 5. Plant: Multicellular eukaryotic autotrophs with cell walls composed of cellulose. 6. Animal: Multicellular eukaryic heterotrophs that do not have cell walls. SPECIATION is the process by which new species arise. There are two mechanisms that can lead to new species: o Reproductive Isolation: Isolation WITHOUT the presence of a physical barrier. (Example: One group of individuals only mates in the fall, and another only reproduces in the spring.) A SPECIES is a group of individuals that can interbreed and produce fertile offspring. The horse and zebra are both members of their own species. How do we know? When we force them to mate, their off spring (a zebroid) is not fertile. Evidence for Evolution ****Scientists have 3 areas of focus that provide evidence for evolution.**** 2. Anatomy 3. Biochemistry Scientists can use layers of undisturbed rock to determine the relative age of fossilized organisms. The OLDEST fossils will always be at the bottom of the column and the YOUNGEST at the top. This technique is called the PRINCIPLE OF SUPERPOSITION. HOMOLOGOUS STRUCTURES: Structures that look SIMILAR to one another. These demonstrate descent from a COMMON ANCESTOR (Divergent Evolution). 1. Fossils. Evolution o Geographic Isolation: the physical separation of species populations by geographic barriers (Example: oceans and mountains) ****EVOLUTION is the process by which species change over time. It s brought on by the process of NATURAL SELECTION. Natural selection allows for individuals with certain traits to successfully survive and reproduce, passing those traits to the next generation.**** ANALOGOUS STRUCTURES: Different structures that perform similar functions. The environment forces unrelated individuals to develop structures to perform similar function. NO COMMON ANCESTOR! (Convergent Evolution) Remember: Organisms that have more DNA in common are closely related! This means that organisms that have more proteins in common are also closely related. Look at the amino acid chain of unknown animal: Met Gly Ser Tyr Tyr Arg His His Glu Lys It most closely resembles? Horse: Met Gly Ser Ser Tyr Arg Arg Asp His Glu Dog: Met Gly Ser Tyr Tyr Arg His Asp Glu Lys Cat: Met Gly Ser Tyr Tyr Arg His His Arg Cys Mouse: Met Gly Ser Tyr Tyr Arg His Glu Val Val Our unknown animal is most closely related to the dog! There s only 1 difference in the protein sequence. Met Gly Ser Tyr Tyr Arg His Asp Glu Lys