Malumoti ohirin
Home / Biologiya / EVOLYUTSIYAI PROTOBIONTHO

EVOLYUTSIYAI PROTOBIONTHO

Agar farziyahoi tasvirshudaro tahlil kunem, ba khulosa omadan mumkin ast, ki inkishofi in guna sistemahoi bo ham tasirrasoni «avtomathoi» organiki tabiati tobiologi doshta, bo rohi gunogun raftaast va muddati khele ziyod davom kardaast. Vale samthoi muhimi evolyutsiyae, ki ba paydoishi sistemai biologi ovarda rasonid, yakchandtoyand: evolyutsiyai protobiontho, paydoishi katalizatorhoi faoli safedavi, paydo shudani kodi genetiki va usulhoi tabdilyobii energiya.

Paydoishi sistemahoi energetiki

Dar sharoiti Zamin omili asosie, ki tavassuti on dar mahluli obi reaksiyai molekulahoi khurdi organiki ba amal meoyad, payvastshavii in molekulaho bo shaklhoi gunoguni fosfa tho meboshad. Dar vaqti guzaronidani guruhhoi fosfati energiya khorij yo furu burda meshavad, az hamin sabab, dar sistemahoi biologi energiya zakhira shuda, bad on dar reaksiyai kondensatsiya yo mubodilai modda istifoda megardad. Holo aloqahoi serenergiyavie, ki bayni fosfatho va payvastagihoi organiki hosil meshavand, guzashtani hamai reaksiyahoi biologiro tamin mesozand. Az ehtimol dur nest, ki in ba hujayrai sodda yo protohujayra niz dakhl doshta boshad.

Bisyor biomolekulahoi khurdi organiki bo ishtiroki miqdori ziyodi ob faqat dar mavridi faol sokhtan bo fosfat ba chunin reaksiya dokhil meshavand. Pas, in tavr boshad, sintezi polimerhoro dar hujayrahoi sodda, payvastagihoi mobaynii fosfathoi faol niz tamin menamoyand. Reaksiyai kondensatsiya bo judoshavii ob ba ravandi biokhimiyavii hozirazamon khos nest. Reaksiya bo guzaronidani fosfat boshad, imruz va dar guzashta niz rohi yagonai ba vujud ovardani kondensatsiyai monomerho meboshad. Baroi guzashtani reaksiyai dokhilshavii fosfat manbai serenergiyai fosfat zarur ast, ki shakli odditarini on pirofosfat meboshad.

In molekula dar mahluli obi noustuvor ast va baroihamin ba khujayrai oddi faqat fosfati halshudai gayriorganiki dastras ast. Dar rafti evolyutsiya zanjirhoi daroztari polipeptidie, ki qobiliyati tezonidani ravishi reaksiyahoi muayyani khimiyaviro doshtand, intikhob karda meshud.

Pirofosfati baroi reaksiya zarur az kujo girifta meshavad? Ehtimol, hosilshavii pirofosfat yake az khosiyati muhimi metabolizmi avvalini hujayrahoi sodda boshad. Hujayrahoi fotosintezkunandai hozira ba sifati jamkunandai (akkumulyatori) energiya adenozintrifosfatro az adenozindifosfat sintez mekunand. In ravand nisbat ba mekhanizmi hosil kardani pirofosfat, ki baroi hujayrahoi sodda khos ast, sermahsultar meboshad. Ivazshavii reaksiyai kondensatsiya bo judo shudani ob, reaksiya bo guzaronidani fosfat asosi ravandhoi biokhimiyavi dar hama organizmhoi imruza vujud doshta, az hujayrai yakumini sodda ogoz yoftaast.

Holo imkoniyati tashkil dodani namunai (modeli) ba haqiqat nazdiki hujayrai soddai davrahoi peshin dar oban borhoi khurd vujud dorad. Ammo in hujayrahoi sodda az on chize, ki imruz hujayra menomem, ba kulli farq dorand, zero onho doroi dastgohi genetiki va sintezi safeda nestand.

Har yak polimeri muvaqqatii dar hujayrai sodda sintezshu da, dar sharoiti behtarin dar kadom yak rishtai (silsilai) nasl faqat az yak hujayra ba hujayrai digar doda shuda, pas az muddate vayron meshavad. Hanuz Foks soli 1992 nishon  doda bud, ki molekulahoi ikhtiyoran tashkilyoftai polipeptidi az sababi dar sathi ruypushi onho mavjud budani zaryadhoi gunogun, bisyor khosiyathoi nomakhsusi faoli katalizi dorand. ,

Az hamin sabab, protobionthoi peptid-hoyashon gunogun dar sharoiti musoid vujud dorand, zero broi tabdil dodani molekulahoi az berun dokhilshuda imko  niyati onho beshtar ast. Agar dar chunin mavridho molekulai safeda hamchun katalizator chi qadar faol boshad, vay baroi sohibi (barandagi) on hamon qadar sudmand mebud.

Ehtimol, dar hamin davra barqarorshavii kodi genetiki ba amal omadaast, yane hamon shakli KDN va KRN-e, ki sistemai nukleotidhoyashon akhbori muhimro ba monandi faoliyati katalizatori molekulai safeda meburd.

Загрузка...

Dar boramon

Инчунин кобед

organizmho

AFZOISH VA INKISHOFI ORGANIZMHO

Afzoish yake az khosiyathoi muhimi olami organiki meboshad. Afzoish ba hamai makhluqoti zinda, az bakteriyaho …