Chemist yana da hanci

A cikin labarin da ke ƙasa, za mu kalli matsalar wari ta wurin likitan chemist - bayan haka, hancinsa zai kasance da amfani a cikin dakin gwaje-gwaje a kullum.

1. Innervation na mutum hanci - wani kauri sama da kogon hanci ne olfactory kwan fitila (marubuciya: Wikimedia/Opt1cs).

Za mu iya raba ji ta zahiri (gani, ji, taba) da kuma na farko sinadaranwatau dandano da kamshi. Domin na farko, an riga an halicci analogues na wucin gadi (abubuwa masu haske, microphones, na'urori masu aunawa), amma na ƙarshe bai riga ya mika wuya ga "gilashin da ido" na masana kimiyya ba. An halicce su biliyoyin shekaru da suka wuce lokacin da sel na farko suka fara karɓar siginar sinadarai daga muhalli.

Ƙanshi a ƙarshe ya rabu da dandano, kodayake wannan baya faruwa a cikin dukkan kwayoyin halitta. Dabbobi da tsire-tsire koyaushe suna shakar kewayen su, kuma bayanan da aka samu ta wannan hanyar sun fi mahimmanci fiye da yadda ake gani a farkon kallo. Har ila yau ga masu koyon gani da ji, gami da mutane.

Sirrin kamshi

Lokacin da kake shaka, rafin iska yana shiga cikin hanci kuma, kafin ya ci gaba, ya shiga wani nama na musamman - epithelium mai ƙanshi da yawa santimita a girman.². Anan akwai ƙarshen sel jijiya waɗanda ke kama warin motsa jiki. Siginar da aka karɓa daga masu karɓa tana tafiya zuwa kwandon wari a cikin kwakwalwa, kuma daga nan zuwa wasu sassan kwakwalwa (1). Ƙunƙarar yatsa ya ƙunshi ƙirar ƙamshi musamman ga kowane nau'in. Mutum zai iya gane kusan 10 daga cikinsu, kuma ƙwararrun ƙwararrun masana'antar turare za su iya gane wasu da yawa.

Kamshi yana haifar da halayen jiki, duka biyun suna sane (misali, kuna firgita da mummunan wari) da kuma a hankali. Masu kasuwa suna amfani da kundin adireshi na ƙungiyoyin turare. Manufar su ita ce dandana iska a cikin shaguna tare da ƙanshin bishiyoyin Kirsimeti da gingerbread a lokacin kafin Sabuwar Shekara, wanda ke haifar da motsin rai mai kyau a cikin kowa da kowa kuma yana ƙara sha'awar siyan kyaututtuka. Hakazalika, warin burodin da ke cikin sashin abinci zai sa ɗigon ku ya ɗigo a cikin bakin ku, kuma za ku ƙara ƙarawa a cikin kwandon.

2. Ana yawan amfani da Kafur wajen dumama man shafawa. Mahalli guda uku masu tsari daban-daban suna da nasu kamshin.

Amma menene ya sa wani abu da aka bayar ya haifar da wannan, ba wani ba, jin ƙanshi?

Don dandano mai ƙanshi, an kafa nau'o'in asali guda biyar: gishiri, zaki, daci, mai tsami, oun (nama) da kuma adadin nau'in masu karɓa a kan harshe. A wajen wari kuwa, ba a ma san adadin kamshin nawa ba, ko kuma akwai su. Tsarin kwayoyin halitta tabbas yana ƙayyade warin, amma me yasa mahadi masu kama da tsarin suna wari gaba ɗaya (2), kuma gaba ɗaya ba su da kama - iri ɗaya (3)?

3. Abin da ke gefen hagu yana wari kamar miski (kayan turare), kuma a gefen dama - kusan iri ɗaya a tsarin - ba shi da wari.

Me yasa yawancin esters suna jin ƙanshi mai daɗi, amma mahaɗan sulfur ba su da daɗi (wataƙila za a iya bayyana wannan gaskiyar)? Wasu ba su damu da wasu wari ba, kuma a kididdiga mata suna da hanci fiye da maza. Wannan yana nuna yanayin kwayoyin halitta, watau. kasancewar takamaiman sunadaran a cikin masu karɓa.

A kowane hali, akwai tambayoyi da yawa fiye da amsoshi, kuma an ƙirƙira ra'ayoyi da yawa don bayyana asirin ƙamshi.

Maɓalli da kullewa

Na farko yana dogara ne akan ingantacciyar hanyar enzymatic, lokacin da reagent molecule ya shiga cikin rami na kwayoyin enzyme (cibiyar aiki), kamar maɓalli na kullewa. Don haka, suna wari ne saboda siffar kwayoyin halittarsu ya yi daidai da ramukan da ke saman masu karɓa, kuma wasu rukunin atom ɗin suna ɗaure ga sassansa (haka ma enzymes suna ɗaure reagents).

A taƙaice, wannan ka'idar wari ce da wani masanin kimiyyar halittu na Biritaniya ya haɓaka. John E. Amurea. Ya ware manyan kamshi guda bakwai: kafur-musky, na fure, da minty, da ethereal, da yaji da kuma gurbacewa (sauran haduwar su). Molecules na mahadi masu irin warin suma suna da irin wannan tsari, alal misali, masu kamshin siffar siffa kamar kafur, da mahadi masu wari mara daɗi sun haɗa da sulfur.

Ka'idar tsarin ta sami nasara - alal misali, ta bayyana dalilin da yasa muke daina wari bayan ɗan lokaci. Wannan ya faru ne saboda toshe duk masu karɓa ta ƙwayoyin da ke ɗauke da warin da aka ba su (kamar dai a cikin yanayin enzymes waɗanda ke mamaye su ta hanyar wuce gona da iri). Duk da haka, wannan ka'idar ba koyaushe tana iya kafa alaƙa tsakanin tsarin sinadarai na fili da ƙamshinsa ba. Ta kasa tantance warin abun tare da isashen yuwuwar kafin ta samu. Har ila yau, ta kasa yin bayanin tsananin ƙamshin ƙananan ƙwayoyin cuta irin su ammonia da hydrogen sulfide. Canje-canjen da Amur da magajinsa suka yi (ciki har da haɓaka yawan abubuwan dandano na tushe) bai kawar da duk gazawar ka'idar tsarin ba.

kwayoyin girgiza

Atom ɗin da ke cikin ƙwayoyin cuta koyaushe suna rawar jiki, suna miƙewa da lanƙwasawa tsakanin juna, kuma motsi baya tsayawa ko da a cikakkiyar yanayin zafi. Molecules suna ɗaukar kuzarin girgiza, wanda ya ta'allaka ne a cikin kewayon infrared na radiation. An yi amfani da wannan gaskiyar a cikin IR spectroscopy, wanda shine daya daga cikin manyan hanyoyin da za a ƙayyade tsarin kwayoyin halitta - babu wasu mahadi daban-daban guda biyu tare da nau'in IR iri ɗaya (sai dai abin da ake kira isomers na gani).

Masu halitta Ka'idar girgiza (J.M. Dyson, RH Wright) sami alaƙa tsakanin mitar girgizawa da ƙamshin da ake gani. Jijjiga ta hanyar rawa yana haifar da girgizar ƙwayoyin masu karɓa a cikin epithelium na olfactory, wanda ke canza tsarin su kuma yana aika motsin jijiya zuwa kwakwalwa. An ɗauka cewa akwai kusan nau'ikan masu karɓa guda ashirin kuma, sabili da haka, adadin adadin ƙamshi na asali.

A cikin 70s, masu goyon bayan ra'ayoyin biyu (vibrational and structural) sun yi fafatawa da juna.

Masana ilimin jijiyoyi sun bayyana matsalar warin ƙananan ƙwayoyin cuta ta yadda baƙaƙensu ya yi kama da gutsuttsuran ɓangarorin manyan ƙwayoyin cuta masu kama da wari. Duk da haka, sun kasa bayyana dalilin da yasa wasu isomers na gani da ke da nau'i iri ɗaya suna da wari daban-daban (4).

4. Isomers na gani na carvone: grade S yana wari kamar cumin, grade R yana warin kamar mint.

Masu tsarin tsarin ba su da wahala wajen bayyana wannan gaskiyar - masu karɓa, suna aiki kamar enzymes, suna gane ko da irin wannan bambance-bambancen da ke tsakanin kwayoyin halitta. Ka'idar jijjiga kuma ba za ta iya yin hasashen ƙarfin warin ba, wanda masu bin ka'idar Cupid suka bayyana ta ƙarfin ɗaure masu ɗaukar wari ga masu karɓa.

Yayi kokarin ceto lamarin L. Torinoyana ba da shawarar cewa epithelium na olfactory yana aiki kamar na'urar duba microscope (!). A cewar Turin, electrons suna gudana tsakanin sassan mai karɓa lokacin da akwai guntun ƙwayar ƙamshi a tsakanin su tare da wani mitar girgizar girgiza. Sakamakon canje-canje a cikin tsarin mai karɓa yana haifar da watsawar jijiya. Duk da haka, gyare-gyaren Turin yana da alama ga masana kimiyya da yawa ma almubazzaranci ne.

Tarkuna

Ilimin halittun kwayoyin halitta ya kuma yi kokarin tona asirin wari, kuma wannan binciken an ba shi lambar yabo ta Nobel sau da yawa. Masu karɓar warin ɗan adam dangi ne na kusan nau'ikan sunadaran sunadaran dubu, kuma kwayoyin halittar da ke da alhakin haɗawar su suna aiki ne kawai a cikin epithelium mai ƙanshi (wato, inda ake buƙata). Sunadaran masu karɓa sun ƙunshi sarkar amino acid mai murɗaɗi. A cikin hoton dinkin, sarkar sunadaran suna huda kwayar halittar tantanin halitta sau bakwai, saboda haka sunan: bakwai-helix transmembrane cell receptors ().

Gutsutsun da ke fitowa a wajen tantanin halitta suna haifar da tarko wanda kwayoyin halitta masu daidaitaccen tsari za su iya faɗowa (5). Ana makala wani takamaiman sunadaran G-nau'in zuwa wurin mai karɓa, a nutse a cikin tantanin halitta, lokacin da aka kama warin kwayoyin a cikin tarkon, G-protein ɗin yana kunna shi kuma ya saki, sannan kuma a haɗa wani G-protein a wurinsa. wanda aka kunna kuma aka sake sakewa, da dai sauransu. Cycle yana maimaitawa har sai an saki kwayoyin ƙamshin da aka ɗaure ko kuma ta rushe ta hanyar enzymes waɗanda ke tsaftace saman epithelium na ƙamshi akai-akai. Mai karɓa na iya kunna ko da ɗaruruwan ƙwayoyin G-protein, kuma irin wannan babban siginar haɓakar siginar yana ba shi damar amsa ko da adadin abubuwan dandano (6). G-protein da aka kunna yana fara zagayowar halayen sinadarai waɗanda ke haifar da aika motsin jijiya.

5. Wannan shine abin da mai karɓar wari yayi kama - protein 7TM.

Bayanin da ke sama game da aiki na masu karɓar olfactory yayi kama da wanda aka gabatar a cikin ka'idar tsarin. Tun da daurin kwayoyin yana faruwa, ana iya jayayya cewa ka'idar jijjiga ita ma ta kasance daidai. Wannan ba shine karo na farko a cikin tarihin kimiyya ba cewa ka'idodin da suka gabata ba gaba ɗaya ba daidai ba ne, amma kawai sun kusanci gaskiya.

6. Human hanci a matsayin mai gano mahadi a cikin bincike na chromatographically rabu garwayayye.

Me yasa wani abu yake wari?

Akwai wari da yawa fiye da nau'ikan masu karɓan wari, wanda ke nufin cewa ƙwayoyin wari suna kunna sunadaran sunadaran da yawa a lokaci guda. bisa ga dukkan jerin sigina da ke fitowa daga wasu wurare a cikin kwanon kamshi. Tun da ƙamshi na halitta ya ƙunshi ko da fiye da mahadi ɗari, wanda zai iya tunanin irin rikitarwa na tsarin samar da jin dadi.

To, amma me yasa wani abu ke wari mai kyau, wani abu mai banƙyama, kuma wani abu maras kyau?

Tambayar rabin falsafa ce, amma an amsa wani bangare. Kwakwalwa ce ke da alhakin fahimtar wari, wanda ke sarrafa halayen mutane da dabbobi, yana mai da sha'awar su ga wari mai daɗi da gargaɗi game da abubuwa masu wari. Ana samun wari mai ban sha'awa, a tsakanin sauran abubuwa, esters da aka ambata a farkon labarin ana fitar da su ta 'ya'yan itatuwa masu girma (don haka suna da daraja a ci), kuma ana fitar da mahadi na sulfur daga ragowar lalacewa (mafi kyawun nisantar su).

Iskar ba ta jin wari domin ita ce bangon da wari ke yaɗuwa: duk da haka, gano adadin NH3 ko H.₂S, kuma jin warin mu zai yi ƙararrawa. Don haka, fahimtar wari alama ce ta tasirin wani abu. dangantaka da nau'in.

Menene kamshin hutun da ke tafe? Ana nuna amsar a hoton (7).

7. Ƙanshin Kirsimeti: a gefen hagu, abincin gingerbread (zingerone da gingerol), a dama, bishiyoyi Kirsimeti (bornyl acetate da nau'i biyu na pinene).