The effect of temperature activity of salivary amylase on starch.pdf

The effect of temperature activity of salivary amylase on starch. By Dev Mandal
Chemistry Investigatory Project

1. ChemistryInvestigatoryProjectAISSCE2022-23Topic:-Theeffectoftemperatureactivityofsalivaonstarch.Name:DevMandalClass:XIIRollno:Subjectandcode:Chemistry(043)Directedby:-Mr.NishitKumarPriyadarshi
ODISHAADARSHAVIDYALAYAGONDHIPALLY,MALKANGIRIPincode:-764045

2. REFERENCES1.ChemistryLaboratoryManualofclass12byNCERT2.AMRITAVishwaVidyapeetham3.OLABSEducation4.CDAC,Mumbai5.NCERTatFINGERTIPS(Biology)class11byMTGteam.

3. TABLEofCONTENTS1.Introduction2.Workingofsalivaryamylase3.EffectofTemperature4.EffectofpH5.Experiment5.1Aim5.2Apparatus&MaterialsReqiured5.3Theory5.4Procedure5.5Observations6.Conclusion

4. Introduction
Alllivingbeingsneedenergytosurvive.Itisfromthefoodweconsumethatwegetourenergy.Weknowthattheenergywearegettingisbytheprocessofdigestionthatbreaksdownthecomplexsubstanceofstarchintosimplermoleculesofglucose,whicharefurthermetabolizedintoCO2andwaterthroughtheprocessofglycolysis.Thehumandigestivetractstartsatthemouthandendsattheanus.
WorkingofSalivaryAmylase
Thedigestionofthefoodstartsassoonasweputfoodinourmouth.Ourteethcutthefoodintosmallpiecesandthesalivaryglandssecretesalivathatmixeswiththesefoodmaterials.Thesalivacontainsanenzymecalledsalivaryamylasewhichhydrolysesstarchintomaltose.Thesalivasecretedintooralcavitycontainselectrolytes(Na
+
,K
+
,Cl
-
,HCO3
-
)andenzymes,salivaryamylaseandlysozymeThechemicalprocessofdigestionisinitiatedin

5. SalivaryAmylasepH6.8
theoralcavitybythehydrolyticactionofthecarbohydratesplittingenzyme,thesalivaryamylase.Salivaryamylaseconvertsstarchintomaltose,isomaltoseandsmalldextrinscalled'α'dextrins.About30percentofstarchinthefoodishydrolysedintheoralcavity.Lysozymepresentinsalivaactsasantibacterialagentthatpreventsinfections.Starch Maltose+Isomaltose+α-Dextrins
Thecompletedigestionofstarchoccursonlyinthesmallintestinebytheactionofpancreaticamylase.
Theactivityofenzymesisstronglyaffectedbyseveralfactors,suchastemperatureandpH.

6. EffectofTemperature
Allenzymesareproteinaceousinnature.Atalowertemperature,theenzymesalivaryamylaseisdeactivatedandatthehighertemperature,theenzymeisdenaturated.Therefore,moretimewillbetakenbyanenzymetodigestthestarchatlowerandhighertemperatures.Optimumtemperaturefortheenzymaticactivityofsalivaryamylaserangesfrom32°Cto37°C.Theoptimumtemperaturemeansthatthetemperatureatwhichtheenzymeshowsthemaximumactivity.Atthisoptimumtemperature,theenzymeismostactiveandhence,takeslesstimetodigestthestarch.
EffectofpH
TheoptimumpHfortheenzymaticactivityofsalivaryamylaserangesfrom6to7.Aboveandbelowthisrange,thereactionratereducesasenzymesgetdenaturated.TheenzymesalivaryamylaseismostactiveatpH6.8.Ourstomachhashighlevelofaciditywhichcausesthesalivaryamylasetodenatureandchangeitsshape.Sothesalivaryamylasedoesnotfunctiononceitentersthestomach.

7. Experiment
Aim
Inordertostudytheeffectoftemperatureonthedigestionofstarchbysaliva
MaterialsRequired
Threeseriesoftesttubeshavingiodinesolutionineach,testtubes,icecubes,water,15ml1%starchsolution+3ml1%NaCl,salivasolution,droppers,thermometer,Bunsenburnerandwiregauze.Takeabout20-30mLofwarmdistilledwater(30°C–40°C)inthemouthandmixitwiththesalivabygarglinginthemouth.Collectthesalivamixedwaterinabeaker.
Procedure
1. Take10mLofthestarchsolutioninaboilingtubeandadd2mLof1%sodiumchloridesolutioninit.2. Keeptheboilingtubeinawaterbath,maintainedat30°–40°C,foratleast15minutes.3. Pour2mLofthesalivasolutionintheboilingtubeandstartthestopwatch

8. immediately.4. Takeout2-3dropsofthemixtureafteroneminuteandpouritinthetesttubecontainingiodinesolution.5. Shakethecontentsofthetesttubeandnotethecolourofthesolution,ifany.Similarly,takeout2-3dropsofthemixturefromtheboilingtubeaftereveryoneminuteandaddtoiodinesolutioncontainedinthetesttubes.6. Recordthecolourofthesolutionineachcase.7. Stoptakingreadingswhenthereisnochangeincolour.8. Recordthereadingsinatabularform.Inordertostudytheeffectoftemperatureonthedigestionofstarchbysaliva,performtheaboveexperimentat50°C.9. TheeffectofpHofreactionmediumcanalsobestudiedbyusingsmallquantitiesofdiluteHClanddiluteNaOHintheseparateexperimentscarriedoutinthesamemannerasabove.
Result
TheeffectoftemperatureandpHontheactivityofsalivaryamylaseonstarchcanbestudiedbyusingtheIodinetest.Ifweaddsalivaonstarch,thesalivaryamylasepresentinsalivagraduallyactsonstarchandconvertsitintomaltose.Starchkeepsongivingbluecolourwithiodinetillitiscompletelydigestedintomaltose.Atthispoint,nobluecolourisformed.Thisistheendpointor

9. achromicpoint.Ittakeslesstimetoreachachromicpointat37°C,astheenzymeismaximumactiveatthistemperature,whileathigherandlowertemperaturesmoretimeistakentoreachtheachromicpoint.
Conclusion
Allenzymesareproteinaceousinnature.Atlowertemperatures,theenzymesalivaryamylaseisdeactivatedandathighertemperatures,theenzymeisdenaturated.Therefore,moretimewillbetakenbyenzymetodigestthestarchatlowerandhighertemperatures.At37°C,theenzymeismostactive,hence,takeslesstimetodigestthestarch.
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