Menene ka'idar chemosynthetic? Mahimman abubuwa da gwaji

Mutum ɗan adam ne mai rikitarwa, wanda baya ga biyan buƙatunsa na yau da kullun, kuma yana buƙatar bayanin wanzuwarsa da asalinsa. Daga nan ne post-post daban-daban suka taso, daga bangaren addini da falsafa, zuwa na kimiyya. A cikin yanayin kimiyya, ka'idar juyin halittar rayuwa da ake kira ka'idar kimiyar sinadarai an lika ta, bisa ga binciken masana kimiyya Alexander Oparin da John Haldane, wanda duk da cewa basu yi aiki tare ba suka zo akan kirkira iri daya, wanda yake bayar da ci gaba ga tushe wanda aka tashe shi a cikin ka'idar babban kara, yana adawa da ka'idar tsara kwari, da kuma ra'ayoyin addini game da yadda rayuwa take.

Menene ka'idar ilimin halittar jiki?

Wannan ka'idar tana cewa hydrogen (H2) wanda yake cikin yanayi na farko ya amsa tare da carbon, nitrogen ko atoms na oxygen wanda ke samar da romo mai gina jiki, wanda yayin saduwa da wasu hanyoyin samun karfi na zamani ya haifar da amino acid da yawa, wanda shine asalin tubalin ginin rayuwa.

Yanayi a cikin yanayi bisa ga sunadarai sunadarai

Ka'idar ilimin sunadarai ta tabbatar da cewa yanayin dadadden yanayi ya kasance yana da halaye wadanda suka fi dacewa da halayen raguwa, tunda idan yanayi mai yanayin juzu'i ya kasance, abubuwan da ke cikin "-An fari na miya" da sun wulakanta. A dalilin haka ne masana kimiyya wadanda suka kirkiro wasu dabarun ka'idar juyin halitta suka tabbatar da cewa a yanayin farko na duniya ba zai iya ba oxygen ya wanzu, tunda halayen maye gurbi bazai inganta cigaban rayuwa ba.

Ka'idojin Chemosynthetic

Matakin shigar da jerin ra'ayoyin ra'ayoyin da suka karye tare da abubuwan da suka gabata na ka'idar tsara kwatsam (wanda aka yarda da shi a zamaninsa) ya faro ne a 1864 sakamakon binciken masanin kimiyyar Faransa Luis Pasteur, wanda ya nuna a cikin gwajinsa cewa “Mai rai yana zuwa ne daga mai rai”, yana haifar da ci gaban sababbin ra'ayoyi. Daga cikin wadancan ra'ayoyin akwai Chemosynthetics, wanda yake bayyana cewa rayuwa ta samo asali ne daga abinda ya shafi sinadarai. Abubuwan da ke cikin wannan bayanan an bayyana su dalla-dalla a ƙasa:

Halittar duniya a farkonta: wannan ka'idar tayi la’akari da cewa a farko, duniya tana da wani yanayi da yake babu isashshen oxygen, kasancewar, duk da haka, yana da wadata a wasu bangarorin, galibi hydrogen (babban taro), don haka ya rage, wanda ya fi dacewa da sakin kwayar halittar hydrogen a cikin jinsin sinadarai da ake dasu. Baya ga wannan, ya na dauke da wasu sinadarai na asali kamar: hydrocyanic acid (HCN), methane (CH4), carbon dioxide (CO2), ruwa (H2O) da sauran kayan aikin.

• Tsarin broth mai gina jiki: kuma aka sani da ɗan fari miya, ya kunshi agglomeration na wani ruwa mai gina jiki wanda duk wadannan abubuwanda aka hada dasu suka gabata. Wannan yawan ruwa ya haifar da tekun farko. Ta yaya wannan ya faru? Ka'idar ilimin kwalliyar kwalliya ta tabbatar da cewa sakamakon sanyin yanayi, akwai wani yanayi na tururin ruwa daga dutsen mai fitad da wuta, wanda ya ja dukkan wadannan abubuwan da shi, tare da samar da romo mai gina jiki, wanda zai tara a cikin damuwa (teku) inda zasu zauna na dogon lokaci ba tare da haɗarin ruɓuwa ba.
• Bayyanar da hadaddun tsarin: A wannan tsarin, aikin hanyoyin samun makamashi daban-daban ya kasance mai mahimmanci, kamar hadari na lantarki, hasken rana da fashewar dutsen mai fitad da wuta. Sakamakon waɗannan halayen sun kasance abubuwa masu haɗari kamar sugars, acid mai ƙima, glycerin da amino acid. Bayan lokaci, juyin halitta ya haifar da tsarin da Oparin ya kira kara tsanantawamafi juriya da ci gaban tsarin halittu wadanda sune magabatan kwayoyin nukiliya na yanzu.

Samuwar coacervates

Oparin ya tabbatar da cewa a tsarin halittar jinsin sunadarai da ke cikin hakan ɗan fari broth, masu tasowa ne suka tashi, wadanda suka kasance hadaddun jinsuna, wadanda a lokacin rabewar kwayar halitta suka dunkule wuri guda, don haka samun membrane da zai maida su halittun na musamman, tare da iya hada kansu (ikon samar da nasu abincin ), wanda zai canza zuwa ingantaccen tsari mai rikitarwa wanda ya zama tsarin rayuwa na gaskiya. Dangane da ka'idar chemosynthetic, wadannan kwayoyin halittu masu asali sune asalin tsirrai da dabbobin duniyar mu.

Da farko, babu wani lemar sararin samaniya, wanda ke kare kwayoyin daga hasken rana kai tsaye. Abin da ya sa ake yarda da cewa mai yiyuwa ne cewa halittar farko an halicce ta ne kuma ba a lalata ta ta hanyar tasirin hasken rana kai tsaye. Bayan miliyoyin shekaru, irin waɗannan ƙwayoyin sun sami damar canzawa zuwa tsarin hadadden tsarin halitta, wanda zai basu damar ninkawa. Daga baya, sun fara hada abincin su ta hanyar amfani da hasken rana, suna aiwatar da aikin daukar hoto da kuma tura iskar oxygen cikin sararin samaniya, wanda daga baya zai zama matakin ozone.

An tsara tsarin ƙirƙirar haɓaka a ƙasa:

• Duk yana farawa ne da samuwar ingantaccen kwayar halitta.
• Yayin da lokaci ya wuce, kwayar halitta ta biyu (macromolecule) ake samu kuma yana daga cikin mawuyacin hali.
• Wannan macromolecule din ya rabu daga hadadden inda ya ga asalinsa.
• Macromolecule yana fara jan hankalin mahaɗan da zai iya ɗaure shi zuwa tsarinta, yana sake ƙirƙirar asalin haɓaka.

Stanley Miller da Harold Urey Gwaji (1953)

Kodayake Oparin da Haldane ne suka kirkiro bayanan da suka hada da kemosynthetic ka'idar a 1924, amma daga baya masana kimiyya biyu sun sake kirkirar wani gwaji a sikeli tare da yanayin yanayi na farko, wanda ya sanya cakuda sinadarin hydrogen, methane da ammonia zuwa fitowar lantarki da yawa, yana hada abubuwa daban-daban. acid. Dalilin wannan gwajin shine nunawa cewa haduwar kwayoyin halitta kwatsam, kuma hakan yafito ne daga kwayoyin sauki wadanda suke cikin yanayin farko.

Don ƙirar gwajin su, sun ɗauki gilashin gilashi suka zuba wani adadi na ruwa, don haka ya cika ta wani ɓangare, an saka cakuda gas ɗin da muka ambata a sama a ciki. Wannan abun ya sha wahalar fitowar lantarki wanda yayi kwatankwacin guguwar zamanin da ya faru a farkon duniya.

Wannan gwajin ya ɗauki mako guda, kuma da zarar ya wuce, ana nazarin sakamakon. Alamar farko ta halayen da ta faru ita ce, an ga canjin launin ruwan, wanda a farkon ya kasance a bayyane, kuma bayan mako guda sai ya sami sautin ruwan hoda, wanda daga baya zai zama launin ruwan kasa, saboda an wadata shi da amino acid da muhimman kwayoyin halitta.

Wannan gwaji gudummawa ce wacce ke tallafawa ka'idar cewa farkon sifofin rayuwa sun samu ne daga halayen sinadarai da aka gudanar kwatsam.