Barobari paydo shudani dastgohi odii genetiki hujayrahoi sodae, ki chunin dastgohro doshtand, qobiliyati sintez kardani polipeptidhoi makhsusro paydo namudaand. Mavjudoti az onho paydogashta oilahoi hujayrahoi sodaro ba vujud ovardand, ki bo ham monand va khosiyati irsi doshtaand va zeri tasiri intikhobi tabii memondand.
On hujayrahoi sodae, ki mavoddi irsi doshtand, imkoniyati khudro baroi sintez kardani safedahoi kaloni vazifaashon guno- gun ziyod kardand. Pas az on ki ba tarkibi hujayrahoi muqarrari chunin molekulahoi vazifai gunogundoshta dokhil shudand, imkoni- yati dar borai tabiati biologii onho sukhan guftan paydo meshavad.
Tavre ki olimon takhmin mekunand, muhiti beruna dar on zamon manbai doimii hosilshavii hamai molekulahoi zarurii mayda bud. Dar natijai bo rohi fotosintez istifoda burdani nurhoi ultrabunafshi Oftob energiyai khimiyavi baroi girif- tani pirofosfat dastras shud. Pas az muhitro ishgol kardani hujayrahoi avvalin fotosintez tagyir yoft.
Baze moddahoi gizoii khurdmolekula nazar ba hosilshavia- shon dar tabiat zudtar istifoda megashtand. Tasiri intikhobi ta- bii nazarras bud, dar natija hamon hujayrahoe bartari paydo me- kardand, ki az muhiti beruna moddahoi lozimaro ziyodtar girifta, onhoro ba moddai gizoii baroi hujayra zarur tabdil medodand.
Umuman, metabolizm az chand zina iborat buda, tavassuti fermentho amali meshavad, dar har zina molekula kamu besh tagy- ir meyobad (to on dame ki moddai zaruri paydo shavad).
Hamai mavjudoti zinda biologi rohi yagonai tabdili biokhi- miyaviro istifoda mebarand, masalan, metabolizmi qand, sinte- zi aminokislotaho, sintez va tajziyai charbho va gayra.
Hususiyati umumi doshtani rohhoi metabolizmro bo du tarz fahmonidan mumkin ast. YAkum, hamai mavjudoti zindai hozira nasli populyatsiyahoi hujayrahoi nakhustini peshguzashta mebo- shand. Duyum, har yak rohi metabolizm dar ravandhoi biokhimiyavii hozira metavonad natijai evolyutsiyai hujayra bahri harchi besh- tar istifoda burdani yagon molekulai baroi khud lozim ravona shuda boshad. Barobari dar ravandi evolyutsiya mukamaltar shu- dani rohhoi metabolizm, bo surati ziyod zinahoi navi ekologi paydo meshavand.
Dar obanborho allakay dar chuqurii chand metr qismi ziyodi nurhoi ultrabunafshro ob furu mebarad, hol on ki rushnoii ba chashm ayon to chuqurihoi beshtar meravad. Tasavvur kardan mumkin ast, ki intikhobi organizmhoi davrahoi avval nisbat ba istifo- dabarii rushnoii ba chashm ayon chi guna bud. Baroi onho muhim- mash mavjud budani khlorofill va sistemai fermenthoi naqli- yotii elektronho ba shumor meraft.
Organizmhoe, ki qobiliyati istifodabarii energiyai rush- noiro dorand, baroi az moddahoi gayriorganiki sintez karda- ni moddahoi organiki afzaliyati beshtar paydo kardand. Hamin tavr, fotosintez paydo shud va in ba paydoishi manbai navi gizo asos guzosht. Masalan, surkhbakteriyahoi anaerobii sulfurii ho- zira dar rushnoi gidrogensulfidro to sulfat oksid mekunand. Gi- drogeni dar natijai in reaksiya khorijshuda baroi to ba angishto- bho va ob barqaror kardani duoksidi karbon istifoda meshavad. Payvastahoi organiki niz metavonand manbai gidrogen boshand. Hamin tavr, organizmhoi autotrofi paydo shudand, vale dar ra- vandi chunin fotosintez oksigen khorij nameshavad. Fotosintez dar bakteriyahoi anaerobi dar marhalai khele barvaqti paydoishi hayot inkishof yoftaast. Bakteriyahoi qobili fotosintez muddati khele daroz dar muhiti beoksigen vujud doshtand. Qadami digari evolyutsiya on bud, ki organizmhoi qobiliyati fotosintez doshta tavonistand obro ba sifati manbai gidrogen istifoda barand. Azkhudkunii autotrofii gazi SO2 az jonibi chunin organizmho khorijshavii O2-ro hamrohi mekard. Organizmhoi nakhustini qo- bili fotosintez, ki oksigenro ba atmosfera khorij mekardand, sianobakteriyaho budand.
Hamin ki hujayrahoi qobili fotosintez rushnoiro ba sifa- ti mavoddi ilovagii fotosintez istifoda burdand, ba atmosfe- ra oksigeni molekulavi judo shud. Bo mururi zamon mavoddi bio- logii oksigen sarfi onro dar davrahoi geologi muayyan mekard. Pardai ozonie, ki nurhoi ultrabunafshro ba Zamin guzashtan namemond, dar qabathoi boloi on taqriban 2 mlrdu 250 mln. sol qabl az oksigen paydo shudaast.
Zeri tasiri oksigeni ozod imkoniyati paydoishi mubodilai oksigenii moddahoe, ki doroi energiyai ziyod budand, ba vujud omad. In holat baroi paydo shudani bakteriyahoi aerobi zamina guzosht.
Hamin tavr, du omile (sianobakteriyaho va rastanihoi sabz) ki sababi dar ruyi Zamin paydo shudani oksigeni ozod shudand, bisyor shaklhoi navi organizmhoi zindaro ba vujud ovardand va onho imkoniyati harchi beshtar istifoda burdani muhiti beruna- ro paydo kardand.
Savolho baroi sanchish:
- Dar obhoi uqyonusi avvalin molekulahoi organikie, ki khosiyati gidrofili (obdusti) va gidrofobi (obro nagz namedidagi) doshtand, chi guna taqsim shuda budand?
- Prinsipi taqsimshavii mahlulro ba fazahoi konsentratsiyai mo- lekulaashon kalon va khurd nombar kuned.
- Qatrai koatservati chist?
- Intikhobi koatservatho dar «shurboi (bulyoni) yakumin» chi guna su- rat megirift?