h3 bio notes

SYLLABUS9816(2021) LEARNINGOUTCOMES1: TheCell andBiomoleculesof Life(a)Describehowthefluidmosaicmodelofthecellhasdevelopedtothecurrentunderstanding(b)Describethebasiccharacteristicsof(i)Prions(ii)Fungi(includingyeastsandfilamentousfungi)(iii)Protoctista(includingalgae)(c)Explainthefollowingtermsanddiscusstheextenttowhicheachconformstothecelltheory(i)Acellularity(includingprionsandviruses)(ii)Multinucleation(includinghyphaeoffilamentousfungi)(iii)Endosymbiosis(includingendosymbioticoriginofeukaryotes)(d)Justifytheneedforcelldifferentiationinmulticellularorganisms(e)Describeproteinbindingsitesandproteinsubunitsinproducinglargeproteinandglycoproteinmolecules(includinghaemoglobin,immunoglobulinandprokaryoticRNApolymerase)(f)Explain,withexamples,howproteinmodification(includingcleavage,phosphorylationandglycosylation)confernewcapabilities(g)Discussandexplainwhyproteinsareabletorecogniseandbindtohighlydiversemolecules,withreferencetothepropertiesandshapesoftheirsurfacesandcleftsthatallowhighlycomplementaryinteractions(h)Discusshowalivingcellregulatesthousandsofenzymes 2: GeneticsandInheritance(a)Discusshowmaturecellscanbereturnedtoastemcellstate(b)Explainthatgeneticengineeringinvolvestheinsertionofagene,obtainedeitherbysynthesisorbyextractionfromanorganism,intoanotherorganism(ofthesameordifferentspecies),suchthatthereceivingorganismexpressesthegeneproduct(c)Explaintherolesofrestrictionendonucleases,reversetranscriptaseandligasesingeneticengineering(d)OutlinetheproceduresforcloningaeukaryoticgeneinabacterialplasmidanddescribethepropertiesofplasmidsthatallowthemtobeusedasDNAcloningvectors(e)ExplainhoweukaryoticgenesareclonedusingE. colicellstoproduceeukaryoticproteins(f)Explainthestructureandrolesofribozymesandtheirpotentialroleingeneticengineering(includingnovelpeptidesynthesisandmodifications)(g)Evaluatethesignificanceofgeneticengineeringtotheworldandhumanity(includingfoodsustainabilityforarapidlygrowingpopulation,diseasetreatmentanddrugdesign)(h)Explainthatepigeneticsisaprocessthataffectstheexpressionofspecificgenes,withoutinvolvingachangeinDNAsequence(i)Discusshowepigeneticshascontributedtothestudyofgeneticsandheredity3: EnergyandEquilibrium(a)Explainhowtheanatomyandphysiologyof theleavesof C4plants, suchasmaize and sorghum, are adapted for high rates of carbon fixation at hightemperaturesintermsof(i)Thespatialseparationofinitialcarbonfixationfromthelight-dependentstage(biochemicaldetailsoftheC4pathwayarerequiredinoutlineonly) DO NOT MONETISE MY SHIT

(ii)Thehighoptimumtemperaturesoftheenzymesinvolved(b)DiscussandcomparetheimportanceinmitigatingglobalwarmingofphotosyntheticcarbonfixationbyC3plants,C4plants,CAMplantsandalgae,includingthoseinreef-buildingcorals(c)ExplainhowthephysiologyoftheleavesofCAMplantsisadaptedtoallowphotosynthesiswhileminimisingwaterlossbytranspiration,intermsof(i)Thetemporalseparationofinitialcarbonfixationfromthelight-dependentstage(biochemicaldetailsoftheCAMpathwayarerequiredinoutlineonly)(ii)Stomatalopeningduringthenight(d)ExplainthechangesinatmosphericoxygenconcentrationduringtheevolutionoflifeonEarthandevaluatetheimportanceofthesechangestoevolution(e)Describeandexplainthetransmissionofanactionpotentialalongamyelinatedneurone(theimportanceofNa + andK + ionsintheimpulsetransmissionshouldbeemphasised)(f)Describethestructureofacholinergicsynapseandexplainhowitfunctions,includingtheroleofCa 2+ ions(g)Explainthatquorumsensingisasystemofsignallingprocessesthatrespondtochangesinpopulationdensityinbacteria(h)Explaintheneedforcontrolinorganisedsystemsandexplaintheprinciplesofhomeostasisintermsofreceptors,effectorsandnegativefeedback(i)Explaintheneedfordifferentcommunicationsystemswithinorganisms 4: Biological Evolution(a)Explain,withexamples,sexualselectionanditssignificanceforevolution(b)Explain,withexamples,theevolutionaryconceptsofadaptiveradiationandringspecies(c)Discussthecontributionsofpolyploidy,hybridisationandintrogressioninevolutionandtheirimplicationsforreconstructingphylogenies(d)Explainthesignificancetolivingorganismsofbiomolecules,includingcarbohydrates,lipids,proteinsandnucleicacids,andthebiochemicalprocessesthroughwhichtheyaresynthesised(e)DiscussthecontributionsofmitochondrialDNAandtheY-chromosomalAdam(theGenographicProject)totraceandsupporttheancestryanddiasporaofhumansA: InfectiousDiseases(a)Explainwhyspecific(adaptive)andnon-specific(innate)immunitycanbebothmutuallyexclusiveandinterdependentintheprotectionagainstpathogens(b)Explainhowimmunologicalself-toleranceensuresthatBlymphocytesandTlymphocytesdonotnormallyattackhostcellsthatarefunctioningcorrectly(c)Explainwhythehumanmicrobiotaisimportantforourhealth(d)Explainthefactorsaffectingtheprobabilitythatapandemicwilloccur,includingsanitation,watersupply,food,climate,large-scalemovementsofpeople,evolutionofnewstrainsofvirulentpathogensanddevelopmentofdrugresistance B: Impact of ClimateChangeonAnimalsandPlants(a)Discusshowhumansarerespondingtomitigateclimatechange,includingbiologicalmeasures(suchastreeplantinganddevelopingdrought-resistantvarietiesofcrops)andlifestylechanges(suchasreducinguseofcarsandconsumptionofmeat)(b)Discuss,withexamples,howanimalandplantspeciescanadjustandadapttoclimatechange,andthepossibleconsequencesofclimatechangeforecosystemsandtheorganismswithintheminthelongerterm DO NOT MONETISE MY SHIT

LO1(a):Describehowthefluidmosaicmodelofthecellhasdevelopedtothecurrentunderstanding. Evidence Conclusion 1807:Linkdemonstratedthatpigmentsfromonecelldidnotpassintoneighboringcellsunlessthecellwallswerebroken1812:Treviranus,MoldenhawerandDutrochetmanagedtoseparatethecellsfromtheplanttissue Cellsarenotsimplyacavity,butunconnectedindependentstructuresboundedbyseparatecellwalls 1895:Overtonimmersedcellsinsolutionsofover500differentsubstancesatthesameconcentration.Henoticedthatsolutionsofether-soluble(apolar)moleculesdidnotresultintheshrinkingofcells,contrarytosolutionsofwater-soluble(polar)substances.Heconcludedthatapolarmoleculesenteredthecellswithlessdifficultythanpolarsubstances,andheshowedthatthiswasirrespectiveoftheirmolecularsize Cellshavesemi-permeablemembranes 1922:Chambersappliedawater-solublecytolysogenicsolutionindifferentpartsofthecell.Hecouldapplythehydrophiliccytolysogenicsubstanceonthesurfaceofstarfisheggswithoutdamagingthem.Whenasmallamountwasinjectedintheinteriorofthecell,cytolysiswasobserved Thenatureofthecellsurfaceischemicallydifferentfromtherestoftheprotoplasm,supportingtheexistenceofthecellmembrane 1925:WhenGorterandGrendelcomparedthesurfacecoveredbythelipidstotheestimatedsumofcellsurfaces,theyfounda2:1ratio Cellsaresurroundedbyalipidbilayer 1941:Deanpostulatedthattheagentofionmovementagainstthegradientcouldresultfromtheactivityofsome“pump”locatedinthemusclefibermembrane1946:Conwayfoundthattheenergynecessarytoextrudeall theNa + fromthemusclewaslarger thantheactualavailableenergyintherestingmuscle Na + /K + asymmetriesacrossthemembranesweretheresultofactivetransportusingionpumps 1971:SingerandNicolsonpresentedthefluidmosaicmodelbasedon(1)thepermeabilityandtransportstudiesthatpredictedenzyme-liketransmembraneproteins(2)theapparentlackoflipidstomakeupcompletebilayers,pointingtotheparticipationofproteinsinthemembraneplane(3)electronmicroscopypictures,includingfreeze-etchingstudiesthatsuggestedthepresenceofproteinswithinthemembranes(4) the stabilityof artificial lipidbilayersthat supportedthemassuitableandsufficient componentstomakeupstructuressimilarinthebiologicalmembranes(5)thefavorableconformationspredictedforthemembraneproteins Fluidmosaicmodelofthecellmembrane DO NOT MONETISE MY SHIT

LO1(b):Describethebasiccharacteristicsofprions,fungi(includingyeastsandfilamentousfungi)andprotoctista(includingalgae).Prions- Definition:misfoldedprotease-resistantprionproteinthatcauseinfectiousneurodegenerativedisordersaffectinganimalsandhumans- Priondiseasescharacterisedbylongincubationperiods,characteristicspongiformchangesassociatedwithneuronalloss,failuretoinduceinflammatoryresponse,rapidlyprogressiveandALWAYSfatal- Abletotransmitbiologicalinformationth