Комрон.инфо
Ravande, ki muqobili sintez ast, dissimilyatsiya – majmui reaksiyahoi tajziya meboshad. Hangomi tajziya shudani payvastagihoi kalonmolekula energiya khorij meshavad, ki baroi reaksiyahoi sintezi biologi zarur ast. Binobar in,
dissimilyatsiyaro mubodilai energetikii hujayraho yo katabolizm (az yunoni katabole – vayronkuni, ba past partoftan) niz menomand.
Energiyai khimiyavii moddahoi gizoi dar bandhoi gunoguni kovalentii bayni atomhoi molekulai payvastagihoi organiki mavjudand. Masalan, hangomi kandashavii chunin bandi khimiyavi – bandi peptidi, qarib 12 kJ dar 1 mol energiya ozod meshavad. Dar glyukoza miqdori energiyai potensiali, ki dar bandhoi bayni atomhoi S, N va O mavjud ast, 2800 kJ-ro dar yak mol (yane dar 180 g glyukoza) tashkil medihad. Hangomi tajziyai glyukoza energiya bo ishtiroki yak qator fermentho davra ba davra muvofiqi muodilai zerin judo meshavad:
C6H12O6 + 6O2 6H2O + 6CO2 > + 2800 kJ
YAk qismi energiya, ki az moddahoi gizoi ozod meshavad, dar shakli garmi parokanda shuda, qismi digar dar energiyai bandhoi fosfatii ATF zakhira megardad. Mahz ATF energiyai hama namudhoi faoliyati hujayraho – sintezi biologi, kori mekhaniki (taqsimshavii hujayra, kashishkhurii mushak-ho), guzaronidani moddaho az membrana, nigoh doshtani potensiali membranavi dar jarayoni intiqoli impulshoi asab, ikhroji usorahoi gunogunro tamin mesozad.
Molekulai ATF az asosi nitrogenii adenin, qandi riboza va se boqimondai kislotai fosfat iborat meboshad (rasmi 4.4). Adenin, riboza va fosfati avvalin adenozin monofosfat (AMF) hosil mekunad. Agar ba fosfati avvalin fosfati duyumin payvast shavad, adenozindifosfat hosil megardad. Molekula bo se boqimondai kislotai fosfat (ATF) beshtar energiyatalab meboshad. Tajziyai okhiri fosfati ATF ba joi 12 kJ, ki hangomi kandashavii bandi oddii khimiyavi judo meshavad, bo khorijshavii 40 kJ meguza-rad. Ba tufayli energiyai ziyodi bandho dar molekulai ATF hujayra metavonad dar fazoi khele khurd miqdori beshtari energiyaro zakhira karda, onro ba qadri zaruri sarf namoyad.
Sintezi ATF dar mitokhondriyaho ba amal meoyad. Az in jo, molekulai ATF ba qismhoi gunoguni hujayra dokhil shuda, energiyai ravandi faoliyati hayotro tamin menamoyad.
