The chemistry of life.docx
- 文档编号:3442771
- 上传时间:2022-11-23
- 格式:DOCX
- 页数:17
- 大小:427.28KB
The chemistry of life.docx
《The chemistry of life.docx》由会员分享,可在线阅读,更多相关《The chemistry of life.docx(17页珍藏版)》请在冰豆网上搜索。
Thechemistryoflife
Thechemistryoflife
InthislensI'dliketotalkyouabouttheChemistryofdailylife.Chemistryisanexcitingexperimentalsciencewhichletsustounderstandourworldandmakesourlifeeasier.Asyouwillreadinthefollowingarticles,chemistryisinoureverydaylife:
inourbody,athome,inthenature...ineverysecondofourlives!
Ifanyofyouhaveaquestionaboutthechemistryofyoureverydaylife,pleasefeelfreetocontactme,andIwillpublishheretheanswerstothosethatmaybeinterestingformostofthepeople.Iinviteyoualsotoleaveacommentinmyguestbookbelow.
ThankyouverymuchtotheSquidoostaffforselectingthislensonApril28thasthe'lensoftheday',Ifeelhonoured!
Iinviteyoualsotovisitmyotherlens:
Spainindepth,andmy website.Thankyou!
GreetingsfromSpain,
Silvia
Howsoapcleans?
Therearesubstanceswhichcanbedissolvedinwater(saltforexample),andothersthatcan't(forexampleoil).Waterandoildon'tmixtogether,soifwetrytocleananoilystainfromaclothorfromtheskin,waterisnotenough.Weneedsoap.
Soapisformedbymoleculeswitha"head"whichlikeswater(hydrophilic)andalongchainwhichhatesit(hydrophobic).
Becauseofthisdualism,soapmoleculesactlikeadiplomat,improvingtherelationshipbetweenwaterandoil.How?
Whensoapisaddedtothewater,thehydrophilicheadsofitsmoleculesstayintothewater(theylikeit!
),whilethelonghydrophobicchainsjointheoilparticlesandremaininwards(escapingfromthewater).Inthatway,theyformcirculargroupsnamedmicellas,withtheoilymaterialabsorbedinsideandtrapped.
Anemulsionofoilinwateristhenformed,thismeansthattheoilparticlesbecomesuspendedanddispersedintothewater.Thus,thoseoilparticlesareliberatedfromtheclothortheskin,andtheemulsionistakenawaywiththerinsing.
Insummary,soapcleansbyactingasanemulsifier.Itallowsoilandwatertomixsothatoilygrimecanberemovedduringrinsing.Therearemorethingsinvolvedinthisprocess,suchasforinstancechangesinthesuperficialtensionofwater,butthisisthegeneralidea.
Vegetablesandcolours-Part1
Whitelightfromthesuncontainsallthewavelengths,butwhenitimpactsonanobjectsomeofitswavelenghtsareabsorbedandsomereflected.Anobjectiscolouredbecauseofthelightthatitreflects.Forexampleredobjectsreflect'red'light,whichislightwithalongwavelength.Manyvegetablesandfruitsarestronglycolouredbecausetheycontainanespecialkindofchemicalcompoundsnamedcarotenoids.Thesecompoundshaveanareacalledchoromophore,whichabsorbsandgivesoffparticularwavelengthsoflight,generatingthecolourthatwethenperceive.
Thechromophoreisformedbyasequenceoflinearcarbon-carbondoublebonds(representedasC=C),muchstrongerthansimplebonds(representedasC-C),sotheatomsremainclosertoeachother.Ingeneral,it'snecessaryatleastsevenlinearconjugateddoublebondsforacarotenoidtoproduceacolour.Besides,thebiggerthenumberofbondsconjugated,thebiggerthewavelengthofthelightabsorbedandalsothemoreredthevegetable,asyoucanseeinthispictureofthelightspectrum:
Thetomatoisredbecauseofthecarotenoidlycopene,whichcontains11conjugatedcarbon-carbondoublebonds.Youcancountthesebondsinthepicturebelow,theyareselectedinred(theatomcarbonsareomitted,onlythebondsareshown).Thiscompoundisgeneratedbytheplanttoprotectitselffromtheairoxidation.Soit'sagoodantioxidantusefulforustoo,protectingourcellsagainsttheactionoffreeradicals(potentoxidants),whichareoneofthemainresponsiblesofcardiovasculardiseases,cancerandaging.
(SeethecontinuationinPart2below)
Vegetablesandcolour-Part2
Thepigmentpresentincarrotsisthebetacarotene,with9linearconjugateddoublebonds,lessthaninlycopenesotheyarenoredbutorange(smallerwavelengththanred,checkitinthespectrumpicture).Thiscompoundisalsoapotentantioxidantandbesidesit'stransformedinourbodyintovitaminA,veryimportantforthemaintenanceofhealthyskin,goodvisionandarobustinmunesystem.
Spinachs,parsleyandplantsingeneralaregreenbecausetheycontainchlorophyll,apigmentwhichenablestheplanttocarryonphotosynthesis,transformingsolarenergyandcarbondioxideintochemicalenergyintheformofcarbohydratesandoxygen.Thisisaprocessessentialforlife.
Asyoucanseeinthepicbelow,thestructureofchlorophyllisverycomplicated,solet'ssimpysaythatitcontainsabigringwithamagnesiumatominthecenter.Curiously,thestructureofhemoglobine(thecarrierofoxygeninourblood)isprettysimilartochlorophyll,thoughithasanatomofironinsteadofmagnesiuminitscenter.
Thechlorophyllmaskstheothercoloursinvegetablesandasitsamountdecreasestherestofcoloursbecomeevident.Thisexplainsforexamplewhytomatoesareinitiallygreenandthenbecomeredwhentheyripen.
ThisisanexampleofhowChemistryiseverywhere,sometimesmoreevident,andsometimesmuchless:
-).
Myguestbook
Please,leaveyourcommentsaboutthislenshere
Iinviteyoutoleaveyouropinionaboutthislensinthisspace,clickingonthe"Submityourownblurb"linkbelow.Youcanalsoaskanyquestionaboutchemistryofdailylife.
I'dlovetoreadyourcomments!
:
-)
------------
submit
∙Reply
mskaylayOct11,2010@10:
15am|delete
Ireallyenjoyreadingyourlenstoday,keepupthegoodwork.
∙Reply
SycroOct9,2010@3:
24pm|delete
Hey
Itriedsooooooooomanytreatmentsforsweatypalmsovertheyears,noneofthemreallyworkedorwerejustashorttermsolution.Howeverwhenifoundnaturalholistictreatments,iknewi'dfoundthecure.
Thanks
sweatypalms
∙Reply
WriterBuzzOct6,2010@5:
42am|delete
Yourlensisgreat.Veryinformative.Ilikedyourlenswithathumbsup.
∙Reply
painkookOct3,2010@9:
37pm|delete
Thumbsup!
Greatlens...veryinformative.Ihavenoideawhywheniwassearchingforbrothertonerandthispoppedupingoogle.I'vebookmarkedthispagetodel.icio.us.Anyway,keepthegreatwork!
∙Reply
alyonamooreAug18,2010@2:
45am|delete
Wonderfulwritingandveryusefulinformation.Thankyou.Imightwanttoaddthatmaintainingabloodpressurechartwillhelpyoutakecontroloveryourheartandensurehealthybloodpressure.
∙LoadMore
ShowAll
∙SharethisGuestbook
oStumbleupon
oFacebook
oMySpace
oTwitter
oDigg
oDelicious
oRSS
oEmail
Whymealsarecookedfasterinapressurecooker?
Apressurecookerislikeanyotherpotbutwithamoreelaboratedlidthatsealsthepotcompletely.Whenyouheatwaterinsidethepotitboilsandthesteamcannotescape,soitremainsinsideandstartstobuilduppressure.Underpressure,cookingtemperaturesraisemuchhigherthanundernormalconditions(higherthantheboilingpointofwater,thatis100ºC),sothenthefoodiscookedmuchfaster.Cookingtimescanbereducedbyafactorofthreeorfour.
Besidescookingfaster,thismethodretainsmorenutrientspresentinthefoodthanothermethods.Anddidyouknowthatapressurecookerisoftenusedbymountainclimbers?
Withoutit,waterboilsoffbeforereaching100ºCbecauseoftheloweratmosphericpressureathighaltitudes,leavingthefoodimproperlycooked.
Whydoonionsmakeyoucry?
Whohasnevercriedwhilecuttinganonion?
(well,apartfromthosewhohavenevercutonehehehe).Thisisalittleexplanationineasyterms.
Insidetheonioncellstherearesomechemicalcompoundsthatcontainsulfur.Whenyoucutanonionitscellsarebrokenandthosechemicalcompoundsthenundergoareactionthattransformsthemintoamorevolatilesulfuredproducts,whicharereleasedintotheair.
Thesesulfuredcompoundsreactwiththemoistureinyoureyesformingsulfuricacid,whichproducesaburningsensation.Thenerveendingsinyoureyesareverysensitiveandsotheypickuponthisirritation.Thebrainreactsbytellingyourtearductstoproducemorewater,todilutetheirritatingacid.Soyoucrytokeepyoureyesprotectedfromtheacid.
Therearesometrickstomakeonion-dicinglessproblematic:
-Choptheonionundercoldwater.Thevolatilesulfuredcompoundswillbereleasedbutthentheyreactwiththewater,insteadofreachingyoureyes.
-Youcanfreezetheonionfor10minutesbeforecuttingit.Thecoldtemperatureoftheonionwillslowdownthechemicalreactionwhichformsthevolatilesulfuredcompunds.
Howtomakeinvisibleinkathome?
Thisisafunnyexperimenttodowithkidsathome.
Youcanplaywithyourkidsathomemakinginvisibleinkwithbasicproductsthatyouhaveinthekitchen.Therearemanymethodstomakeinvisibleink.Thesearesomeoftheeasiestones:
1)Lemonjuicemethod
-Ingredients:
justlemonjuice.
Writeyourmessageonapieceofpaperwithabrushortootpickembeddedinlemonjuice.Letitdrycompletely.
Toreadthemessageheatthepaperforawhile(forinstanceholditclosetoalightbulb)untilthewordsbecomevisible.Warning:
donotholdpapertooclosetotheheatandbecarefulnottoletitgettoohot!
-Chemicalexplanation:
Lemonjuiceisamildacidthatweakensthepaperuponcontact.Sowhenyouheatthepaperthepartwiththejuiceburnsbeforetherestmakingyourmessagevisible.
2)Bakingsodamethod
-Ingredients:
bakingsodaandwaterinsameamount(forinstance30mLofeach).
Mixthemanduseatoothpickorbrushtowriteonapieceofpaper.Waituntilitdriescompletely.
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- The chemistry of life
![提示](https://static.bdocx.com/images/bang_tan.gif)