Fotosintez. Dar bargho hosil shudani ohar

CHi tavre ki shumo allakay medoned, baroi rushdu inkishofi mutadili rastaniho ob, moddahoi madani va organiki nihoyat zarurand.

Ob va moddahoi madaniro rastani az khok qabul mekunad. Vale savole paydo meshavad, ki rastaniho moddahoi organikiro az kujo megirand? Dar natijai tadqiqot malum gardid, ki rastanikho khudashon qobiliyat dorand dar ravshani az moddahoi gayriorganiki (ob va gazi karbonati havo) moddahoi organikiro hosil kunand.

In hodisa ravandi fotosintez nomida meshavad. Fotosintez az kalimai yunony “fotos” — ravshani va “sintezis“ — payvastagi, hosil mekunam, girifta shudaast. Qobiliyati fotosintezkuni dosh- tan in khususiyati mutlaqo farqkunandai rastanihoi sabz meboshad. Tamomi moddahoi organikie, ki dar meva, tukhm, bekhmeva, lundame- va, piyozak va gayraho zakhira meshavand, dar ravandi fotosintez hosil megardand.

Baroi inro fahmidan tajribai zerin kumak merasonad 52:. YAgon rastanii khonagi, masalan guli tutiyo yo anjibar (yorongul)-ro, ki barghoi pahni kalon dorand, girifta 3—4 shabonaruz dar joi (jevoni) torik meguzorem. Bo guzashti in muddat rastaniro az joi torik berun barovarda, ba hardu tarafi yake az barghoi on shakli yagon harfi (bo salohdidi khud) dar kogazi siyoh pas az naqshbandi buri- dashudaro, ki peshaki tayyor karda shudaast, bo zudi mechasponem va nagz mahkam mekunem, to ki dar baynashon ravshani naguzarad. SHumo metavoned sabti “ohar” (krakhmal)-ro, ki dar kogazi siyoh naqshbandi shudaast, istifoda bared. Bad tubaki rastanidorro ba joi ravshani oftobras yo dar nazdi charogi barqi meguzorem. Pas az 6-8 soat bargro burida, kogazi harfdorro az on dur mekunem.

Bargro yakchand daqiqa dar obi jush, bad ba stakani spirtdor andokhta, garm mekunem. Vaqte ki barg berang shud, onro girifta meshuem va dar lalicha pahn mekunem. Ba boloi bargi berangshuda makhduli se- robi yod merezem. Dar bargi berang dar on joyhoe, ki ravshani ra- sidaast, rangi kabud paydo meshavad. YAne, bo tasiri ravshani ohar hosil shudaast. Zero okhar bo tasiri yod rangi kabud paydo mekunad. Zeri kogazi siyohi harfmonand buridashuda boshad, berang mon- dan megirad. Zero ba on jo ravshani dokhil nameshavad (namerasad) va ohar niz khosil nameshavad. Va sabti harf, yo ibora ba khubi ayon megardad. Hamin tavr, okhar faqat dar ravshani dar natijai ravan- di fotosintez hosil meshavad.

Tadqiqotho nishon dodand, ki dar barg avval qand hosil meshavad va on sipas ba ohar va digar moddahoi organiki tabdil meyobad.

Azbaski okhar dar ob hal nameshavad, vay bo tasiri moddahoi makhsusi faol (fermentho) ba qand tabdil yofta, az barg ba digar uzvhoi rastani burda meshavad. Hamin tavr, moddakhoi organikii dar vaqti fotosintez hosilshuda dar gizogirii organikii rasta- niho (gizogirii avtotrofi) faolona shirkat mevarzand.

Aknun savole paydo meshavad, ki oyo dar hamai hujayrahoi barg okhar hosil meshavad? Baroi ba in savol javob dodan chunin tajri- ba meguzaronem. Rastanii anjibari chipor (zero bargash khol-khol joyhoi safedi bekhlorofill dorad)-ro girifta yakchand soat ba zeri rushnoii balandi oftob yo nazdi charogi barqi meguzorem. (Inchunin kanori pahnaki bargash niz zehaki safed dorad). Bad yake az barghoi onro burida girifta, chun dar tajribai dar bolo zikrgardida berang mekunem, Bargi berangshudaro 2-3 daqiqa dar mahlu-li serobi yod nigoh medorem.

Mebinem, ki joyhoi khol-khol safed va zehaki bargi anjibari chipor kabud nashudaast. YAne, dar on joyho okhar hosil nashudaast. Zero dar hujayrahoi sabzi pahnaki barg khloroplastho va dar onho pigmenti khlorofill hast. Dar in khel hujayraho dar ravshani ohar hosil meshavad va bo tasiri yod rangashon kabud meshavad. Dar joyhoi khol-khol va zehaki safedi barg khloroplasthoi khlorofilldor nestand va dar in khel hujayraho ohar hosil nameshavad va bo tasiri yod berang mondan megirand.

Hamin tavr, ohar, qand dar ravshanii oftob dar plastidhoi rangi sabzdoshtai hujayra — khloroplastho hosil meshavand. In hodisaro ravandi fotosintez menomand.

1. Baroi hosil shudani ohar dar barg kadom sharoitho zarurand?
2. Hosilshavii oharro dar barg bo kadom tajriba isbot kardan mumkin ast?
3. CHaro joi bo kogazi siyoh pushondashudai barg bo tasiri yod kabud nameshavad?
4. CHaro dar joyhoi safedrangi bargi anjibari chipor (khol-khol) ohar hosil nameshavad?