Enzyme (Bromelain) activity of Pineapple (fresh and canned) towards Gelatin (guide questions w/ answers)

1. Enzyme at work
1 whatkindof enzyme isinthe pineapple thatworksonthe gelatin?Explain(5)
It isa protein-digestingenzyme called,asagroup, bromelain. The enzyme’s abilitytobreak
downproteinssuchas collagen(whichis the mainmacromoleculecomponentfoundinoursubstrate)
has preventedthe congealingof gelatin,thusmakingitwateryandgraduallylose itsform. Temperature
and pH alsoplaysa role in the effectivenessof the enzyme.
2 explainthe resultsobtainedwithfreshandcannedpineapple (5)
Similarperformance hasbeenobservedbetweenourmanipulative variables(freshandcanned
pineapples) forbothexecutedthe non-congealingeffecttothe gelatin,however adifference intime of
settlementof pineapples inthe bottomhasbeenspottedout—freshpineappleeatsoutthe gelatin
more than the cannedone.Thisis because temperaturecanalsoplaya role inthe effectivenessof an
enzyme,studieshave showedthatbromelaincanbe denaturedbyheat,a processthat hasbeen
undergone byall cannedpineapples.Ineffect,freshpineapplesactout ongelatinthe mostfor ithas
more enzymesatwork.
3 if youuse agar agar (or substrate),willyougetthe same resultsasinabove where you use gelatin?
Why or whynot? (8)
No,a varyingresultwouldbe producedfordifferentamountof proteinispresentbetweenthe
variables.Eventhoughvarioustestshave shownthatbothhasa non-congealingeffectwhenexposedto
pineapples,gelatinjells/setsharderthanthe agaragar. Thisismore likelybecause agarismade out
fromred algae,a substance thathas lessproteincomparedtothe gelatinwhichcontains98-99% (made
mainlyfromcollagen). Differentcookingrecipeshave shownthat anagar can settle withapineapple
dependingonitsratio,more agar-lesspineapple isbeingrecommended,apropertywhichmakesita
favorable substitute forgelatinintermsof mixingw/fruitslike pineapple.
Conclusion
I therefore conclude that enzymesare significantforitcanproduce varyingtraitsdependingon
itsacted substrate. Theyserve ascatalysts,triggeringachemical reactionsothatit can proceedunder
differentconditions.Canbe foundinnatural,“live”foodsandinthe body--designatedasworkforce,
therebymakingmetabolismpossible.
For the experiment,thismade me realizedthatthere are differentfactorsthataffectthe
effectivenessof anenzyme e.g. temperature andpH.Anenzyme canperformitsfunctiononlywhen
matchedto a compatible substrate andthusare highly selective, meaningthateachenzyme onlyspeeds
up a specificreaction.Enzymesare proteincatalystthatcan eitherproduce chemical reactionsthatcan
cut (Catabolism) oradd(Anabolism) substancesincells,thusforthe activitydone,the enzyme
(bromelain)servesthe processof catabolism, eating/cuttingoutthe protein(Collagen)foundingelatin.

2. DNA extraction
1What is the role of the salt?Explain(5)
The salt enablesthe DNA strandstocome together,oraggregate.Once the dishwashingliquidhelps
release the DNA,the saltwill neutralizethe negative chargesonthe DNA therebymakingeachstrandto
sticktogetherinclumpslarge enoughtosee.
2what isthe role of dishwashingliquid?Explain(5)
The dishwashingliquidservesasacatabolizingagent(due tothe presence of sodiumlaurelsulfate) for
the lipids andproteins. Toputintoa situation,thinkof fatsandoils,dishwashingliquid“cutsthrough
grease”because it actuallybreaksdownthe greasymolecules e.g.lipids.Remember,lipidsare the
moleculesthatmake the membranesaroundcellsandthe nucleus(whichholdsDNA),sowhen
dishwashingliquidisadded,the nucleiandcell membrane are brokenaparttherebyreleasingthe DNA,
our mainsubjectforextraction.
3why douse a filter?Justifyyouranswer(3)
We mustuse a filtersothatthe cell wallsandportionsof membraneswouldbe discardedinour
solution. Also,whole cellsthatfailedtobe lysedbythe solubilizingsolutionwouldalsostuckinthe filter.
DNA,proteins,mRNA andanysmall componentsfromcytoplasmwouldhave passedeasilythroughthe
filter.Mostof the filtrate isthe solubilizingsolution,intowhichthe solublecomponentsfrombanana
cell cytoplasmflowed.
4what doesthe coldalcohol do?Can you use roomtemperature orwarm alcohol;whyorwhynot? (7)
The DNA clumpsare soluble (canbe dissolved) insome liquids,butnotinalcohol.So,addingalcohol
helpsthe clumpsof DNA to form.
It isknownthat everything exceptthe DNA willdissolveinethanol.The ethanol pullswaterfrom
the DNA molecule sothatitthencollapsesinonitself andprecipitates.The DNA will becomevisibleas
white mucousstrandsthatcan be spooledwiththe woodenapplicatorstick.
No,we shouldn’tuse roomtemperature orwarmalcohol forthe amountof precipitatedDNA
dependsonthe coldnessof ethanol (the colder- the greaterthe amountof DNA thatcan be spooled).
5 can youuse other fruitsorvegetablesassourcesof DNA?Justifyyouranswer(5)
Yes,
Anymaterial thatcontainslotsof cellswouldbe apossible source of DNA.Bakers’yeastandbacterial
culturescontainlotsof cells.Seedsandgrainsmightalsobe good,since these probablyhave lotsof cells
that are readyto germinate intonextyear’splant.Howevertheyare hardto grindup so notusedvery
often.Animal cells,too,containDNA:one easysource of animal cellsisthe cheekcellsfromstudents’
rinsingtheirmouths!Onthe otherhand,nutswouldnotbe as greatsourcesof DNA since theycontaina
lotof oilsandproteinsasstorage materialsforthe growingplant.A hen’seggwouldbe a terrible source
of DNA since the whole thingcontainslotsof storage materialstonourishagrowingchickbutonlya

3. single cell (thus,verylittleDNA).Spermisanexcellentsource of DNA since ithasveryfew othercellular
components.Howeverinpractical termssome sourcesare easiertoacquire thanothers.