Usokhemisi unekhala

Esihlokweni esingezansi, sizobheka inkinga yephunga ngamehlo omakhemikhali - emva kwakho konke, ikhala lakhe liyoba usizo kuye elabhorethri yakhe nsuku zonke.

1. Ukungena ngaphakathi kwekhala lomuntu - ukujiya ngaphezu komgodi wamakhala ibulb enuka kamnandi (umbhali: Wikimedia/Opt1cs).

Singabelana ngemizwa ngokomzimba (ukubona, ukuzwa, ukuthinta) kanye nesisekelo sazo amakhemikhaliokungukuthi ukunambitha nokuhogela. Okwangaphambili, ama-analogue okufakelwa asevele adalwe (izakhi ezizwela ukukhanya, imakrofoni, izinzwa zokuthinta), kodwa lezi zamuva azikanikeli "ingilazi neso" lososayensi. Zadalwa izigidigidi zeminyaka edlule lapho amangqamuzana okuqala eqala ukuthola izimpawu zamakhemikhali avela endaweni ezungezile.

Iphunga ligcine lihlukene nokunambitha, nakuba lokhu kungenzeki kuzo zonke izinto eziphilayo. Izilwane nezitshalo zihlala zihogela indawo ezikuzungezile, futhi ulwazi olutholakala ngale ndlela lubaluleke kakhulu kunalokho olubonakala ngaso ekuqaleni. Futhi kubafundi ababonwayo nabazwayo, kuhlanganisa nabantu.

Izimfihlo Zephunga

Lapho uhogela umoya, umfudlana womoya ugijimela emakhaleni futhi, ngaphambi kokuba uqhubeke, ufaka izicubu ezikhethekile - i-olfactory epithelium engamasentimitha ambalwa ngosayizi.². Nazi iziphetho zamangqamuzana ezinzwa athatha izisusa zephunga. Isignali etholwe kuma-receptors ihambela isibani sokuhogela ebuchosheni, bese isuka lapho iye kwezinye izingxenye zobuchopho (1). Isihloko somunwe siqukethe amaphethini ephunga aqondene nohlobo ngalunye. Umuntu angabona ezingaba ngu-10 zazo, futhi ochwepheshe abaqeqeshiwe embonini yeziqholo bangakwazi ukubona ezinye eziningi.

Iphunga lidala ukusabela emzimbeni, kokubili ukwazi (isibonelo, wethuswa iphunga elibi) kanye nokunganaki. Abathengisi basebenzisa ikhathalogi yezinhlangano zamakha. Umqondo wabo uwukunambitha umoya ezitolo ngephunga lezihlahla zikaKhisimusi kanye ne-gingerbread ngesikhathi sangaphambi kukaNcibijane, okubangela imizwelo emihle kuwo wonke umuntu futhi kwandise isifiso sokuthenga izipho. Ngokufanayo, iphunga lesinkwa esisha engxenyeni yokudla lizokwenza amathe akho aconsele emlonyeni wakho, futhi uzofaka okuningi kubhasikidi.

2. I-Camphor ivame ukusetshenziswa ekufudumeni amafutha. Izinhlanganisela ezintathu ezinezakhiwo ezahlukene zinephunga lazo.

Kodwa yini ebangela ukuba into ethile ibangele lokhu, hhayi okunye, ukuzwa okunuka kamnandi?

Ngokunambitheka kwephunga, kuye kwasungulwa izinhlobo ezinhlanu zokunambitha eziyisisekelo: okusawoti, okumnandi, okubabayo, okumuncu, i-oun (inyama) kanye nenani elifanayo lezinhlobo zama-receptor olimini. Endabeni yephunga, akwaziwa nokuthi mangaki ama-flavour ayisisekelo akhona, noma ukuthi akhona nhlobo. Isakhiwo sama-molecule ngokuqinisekile sinquma iphunga, kodwa kungani inhlanganisela enesakhiwo esifanayo iphunga elihluke ngokuphelele (2), futhi lihluke ngokuphelele - okufanayo (3)?

3. I-compound ngakwesobunxele iphunga njenge-musk (i-perfume ingredient), futhi ngakwesokudla - icishe ifane ngesakhiwo - ayinalo iphunga.

Kungani ama-ester amaningi ephunga elimnandi, kodwa ama-sulphur compounds angajabulisi (leli qiniso lingachazwa cishe)? Abanye abazwani nhlobo nephunga elithile, futhi ngokwezibalo abesifazane banekhala elizwela kakhulu kunabesilisa. Lokhu kuphakamisa izimo zofuzo, i.e. ukuba khona kwamaprotheni athile kuma-receptors.

Kunoma yikuphi, kunemibuzo eminingi kunezimpendulo, futhi izinkolelo-mbono eziningana ziye zathuthukiswa ukuchaza izimfihlakalo zephunga.

Ukhiye nokukhiya

Eyokuqala isekelwe kumshini ofakazelwe we-enzymatic, lapho i-molecule ye-reagent ingena emgodini we-molecule ye-enzyme (indawo esebenzayo), njengokhiye wokukhiya. Ngakho-ke, bayanuka ngoba ukuma kwama-molecule abo kuhambisana nemigodi engaphezulu kwama-receptors, futhi amaqembu athile ama-athomu abopha ezingxenyeni zawo (ngendlela efanayo ama-enzyme abopha ama-reagents).

Ngamafuphi, lena ithiyori yephunga eyakhiwe isazi samakhemikhali ezinto eziphilayo saseBrithani. John E. Amurea. Uveze amakha ayisikhombisa abalulekile: i-camphor-musky, izimbali, i-minty, i-ethereal, okubabayo kanye ne-putrid (ezinye ziyinhlanganisela yazo). Ama-molecule e-compounds anephunga elifanayo nawo anesakhiwo esifanayo, isibonelo, labo abanomumo oyindilinga banuka njenge-camphor, futhi ama-compounds anephunga elibi ahlanganisa isulfure.

Ithiyori yesakhiwo ibe yimpumelelo - isibonelo, yachaza ukuthi kungani siyeka ukuhogela ngemva kwesikhashana. Lokhu kungenxa yokuvinjwa kwawo wonke ama-receptors ngama-molecule aphethe iphunga elinikeziwe (njengoba nje kwenzeka kuma-enzyme athathwe ngokweqile kwama-substrates). Kodwa-ke, le thiyori ayikwazanga njalo ukusungula ukuxhumana phakathi kwesakhiwo samakhemikhali senhlanganisela kanye nephunga layo. Akakwazanga ukubikezela iphunga lento ngamathuba anele ngaphambi kokulithola. Uhlulekile nokuchaza iphunga elinamandla lama-molecule amancane njenge-ammonia ne-hydrogen sulfide. Izichibiyelo ezenziwe u-Amur nabamlandelayo (kuhlanganise nokwenyuka kwenani lama-flavour ayisisekelo) azizange ziqede zonke izingqinamba zethiyori yesakhiwo.

ama-molecule anyakazayo

Ama-athomu kuma-molecule ahlala edlidliza, enweba futhi egobisa izibopho phakathi kwawo, futhi ukunyakaza akumi ngisho nakumazinga okushisa ayiziro ngokuphelele. Amangqamuzana amunca amandla okudlidliza, atholakala ikakhulukazi kuchungechunge lwemisebe ye-infrared. Leli qiniso lasetshenziswa ku-IR spectroscopy, okungenye yezindlela eziyinhloko zokunquma ukwakheka kwama-molecule - azikho izinhlanganisela ezimbili ezihlukene ezine-spectrum ye-IR (ngaphandle kwalokhu okubizwa ngokuthi ama-isomers optical).

Abadali i-vibrational theory of smell (J. M. Dyson, R. H. Wright) ithole izixhumanisi phakathi kwemvamisa yokudlidliza nephunga elibonakalayo. Ukudlidliza nge-resonance kubangela ukudlidliza kwama-molecule e-receptor ku-olfactory epithelium, eshintsha ukwakheka kwawo futhi ithumele umfutho wezinzwa ebuchosheni. Kwakucatshangwa ukuthi kunezinhlobo ezingamashumi amabili zama-receptors futhi, ngakho-ke, inani elifanayo lamaphunga ayisisekelo.

Ngama-70s, abasekeli bazo zombili izinkolelo (vibrational kanye nesakhiwo) baqhudelana kanzima bodwa.

Ama-Vibrionists achaza inkinga yephunga lama-molecule amancane ngokuthi i-spectra yabo ifana nezingcezu ze-spectra yama-molecule amakhulu anephunga elifanayo. Kodwa-ke, abakwazanga ukuchaza ukuthi kungani amanye ama-optical isomer ane-spectra efanayo enephunga elihluke ngokuphelele (4).

4. Ama-isomer abonakalayo e-carvone: Ibanga S linuka njengekhumini, i-grade R inuka njengeminti.

Izazi zesakhiwo azinabo ubunzima bokuchaza leli qiniso - ama-receptors, asebenza njengama-enzyme, aqaphela ngisho nomehluko onjalo ocashile phakathi kwama-molecule. Ithiyori yokudlidliza nayo ayikwazanga ukubikezela amandla ephunga, abalandeli bethiyori kaCupid abayichaza ngamandla okubopha abathwali bephunga kuma-receptors.

Wazama ukuhlenga isimo L. Torinookuphakamisa ukuthi i-epithelium ephunga isebenza njengesibonakhulu esithwebulayo (!). NgokukaTurin, ama-electron ageleza phakathi kwezingxenye zesamukeli lapho kukhona ucezu lwe-molecule yephunga phakathi kwawo nemvamisa ethile yokudlidliza. Izinguquko eziwumphumela wesakhiwo se-receptor zibangela ukudluliswa kwe-nerve impulse. Nokho, ukuguqulwa kweTurin kubonakala kososayensi abaningi kuyihaba kakhulu.

Izicupho

Isayensi yamangqamuzana ezinto eziphilayo nayo iye yazama ukwembula izimfihlakalo zephunga, futhi lokhu okutholakele kuye kwaklonyeliswa uMklomelo KaNobel izikhathi eziningana. Ama-receptors ephunga lomuntu awumndeni wamaprotheni ahlukene angaba yinkulungwane, futhi izakhi zofuzo ezibhekene nokuhlanganiswa kwazo zisebenza kuphela ku-epithelium ephunga (okungukuthi, lapho idingeka khona). Amaprotheni e-receptor aqukethe iketango le-helical lama-amino acid. Emfanekisweni womthungo, uchungechunge lwamaprotheni lubhoboza ulwelwesi lweseli izikhathi eziyisikhombisa, yingakho kuthiwa: Seven-helix transmembrane cell receptors ().

Izingcezu eziphumela ngaphandle kwengqamuzana zakha ugibe lapho ama-molecule anesakhiwo esihambisanayo angawela khona (5). Iphrotheni ethile yohlobo lwe-G inamathiselwe kusayithi yesamukeli, ecwiliswe ngaphakathi kweseli. Uma i-molecule yephunga ivaleleke ogibeni, i-G-protein iyasebenza futhi iyakhululwa, futhi enye i-G-protein inamathiselwe endaweni yayo. ecushwa futhi ikhishwe futhi, njll. Umjikelezo uphinda kuze kube yilapho i-molecule yephunga eliboshwe ikhishwa noma ibhujiswa ama-enzyme ahlala ehlanza ingaphezulu le-epithelium ephunga. Isamukeli singakwazi ukusebenzisa amakhulu amaningana ama-molecule e-G-protein, futhi isici esinjalo sokukhulisa isignali esiphezulu siyivumela ukuthi iphendule ngisho namanani omkhondo wokunambitha (6). I-G-protein ecushiwe iqala umjikelezo wokusabela kwamakhemikhali okuholela ekuthumeleni i-nerve impulse.

5. Yilokhu okubukeka kwesamukeli sephunga - iphrotheni 7TM.

Incazelo engenhla yokusebenza kwama-olfactory receptors iyafana naleyo ethulwe kumbono wesakhiwo. Njengoba ukuboshwa kwama-molecule kwenzeka, kungaphikiswana ngokuthi ithiyori yokudlidliza nayo yayilungile ngokwengxenye. Lesi akusona isikhathi sokuqala emlandweni wesayensi ukuthi izinkolelo-mbono zangaphambili zazingalungile ngokuphelele, kodwa zivele zisondele eqinisweni.

6. Ikhala lomuntu njengomtshina wezinhlanganisela ekuhlaziyeni izingxube ezihlukene ngokwechromatographically.

Kungani into inuka?

Kunamaphunga amaningi kakhulu kunezinhlobo zama-olfactory receptors, okusho ukuthi ama-molecule ephunga asebenze amaprotheni amaningana ahlukene ngesikhathi esisodwa. ngokusekelwe kulo lonke ukulandelana kwamasignali avela ezindaweni ezithile kusibani sokuhogela. Njengoba amakha emvelo equkethe ngisho nezinhlanganisela ezingaphezu kwekhulu, umuntu angacabanga inkimbinkimbi yenqubo yokudala umuzwa wokuhogela.

Kulungile, kodwa kungani into enuka kahle, into enengekayo, futhi into engekho nhlobo?

Umbuzo uyingxenye yefilosofi, kodwa uphendulwe kancane. Ingqondo inesibopho sokubona iphunga, elilawula ukuziphatha kwabantu nezilwane, iqondise isithakazelo sabo emahogweni amnandi kanye nesixwayiso ngezinto ezinuka kabi. Iphunga elihehayo litholakala, phakathi kwezinye izinto, ama-esters okukhulunywe ngawo ekuqaleni kwalesi sihloko akhululwa izithelo ezivuthiwe (ngakho-ke zifanele ukudla), futhi ama-sulfure compounds akhululwa ezinsalela ezibolayo (okungcono kakhulu ukuhlala kude nazo).

Umoya awunuki ngoba uyingemuva lapho iphunga lisabalala khona: nokho, landelela amanani e-NH3 noma H.₂S, futhi inzwa yethu yokuhogela izokhala i-alamu. Ngakho, umbono wephunga kuwuphawu lomthelela wesici esithile. maqondana nezinhlobo.

Anuka kanjani amaholide azayo? Impendulo ikhonjisiwe esithombeni (7).

7. Iphunga likaKhisimusi: ngakwesokunxele, ama-aromas e-gingerbread (i-zingerone ne-gingerol), ngakwesokudla, izihlahla zikaKhisimusi (i-bornyl acetate nezinhlobo ezimbili ze-pinene).