Menya imikoranire hagati y’urumuri n’ibimera(Photosynthesis)

Photosynthesis ni uburyo ibimera bifata urumuri rw’izuba bikarukuramo ibikoresho nkenerwa byifashisha  mu buzima bwabyo. Izi ngufu ibimera bizihinduramo amasukari yitwa  carbohydrate molecules nayo bikahinduramo andi masukari avanze n’amazi bigakora icyizwi nka Photosynthis.

Kubera ko ibimera byo biba bikeneye carbon, iyo bimaze kuyikora biyivanye mu ruvange rw’urumuri n’aya masukari birekura umwaka wa Oxygen kuko kuri byo uba wahindutse umwanda.

Bimwe mu bimera bikora photosynthesis kurusha ibindi ni ibiba munsi y’inyanja bitagaragarira amaso bita algae(twagereranya n’urubobi cyangwa ibihumyo).

Kubera ko ibimera byohereza oxygen nyinshi mu kirere , ibi bituma abantu n’ibinyabuzima bibona umwuka wo guhumeka kandi bigafasha mu guhangana n’ubwinshi bw’imyuka ihumanya ikirere yoherezwa n’inganda n’ibinyabiziga.

Nubwo bwose amoko atandukanye y’ibimera akora photosynthesis, iyi gahunda ikorwa iyo ingufu zikomoka ku rumuri zimaze kubikwa na za proteins zizwi ku izina rya reaction centers zibitse uduvungukira dusa n’icyatsi twitwa chlorophyll.

Mu kimera cyane cyane ku bimera byera indabo( plantes à fleurs), izi chlorophylls ziba zibitse mu gifuniko bita chloroplasts ari nazo zizamura amasukari ikimera kiba gikeneye ngo gikure . Iki gifuniko nicyo kigize igice kinini cy’ikibabi.

Igiti kirekire kurusha ibindi ku Isi cyitwa Sequoia(gifite metero 90 z’uburebure) nacyo gikura muri ubwo buryo.

Abahanga bemeza ko ibimera bikoresha Photosynthesis bifata toni ziri hagati ya metero kibe  miliyoni 100 na 115  za carbon ikazihinduramo ingufu zifashishwa n’ibimera buri  mwaka.

Ibimera bifata Carbon dioxide bikayihinduramo amasukari bikoresheje icyo bita  carbon fixation.

Kubera iki ibimera bigira ibara ry’icyatsi?

Reka duse nabakoresheje icyuma kireba utuntu duto cyane bita Microscope. Ubundi iyo urebeshe amaso asanzwe ubona ko ibimera byinshi bisa n’icyatsi, ariko burya siko bimeze!

Ukoresheje Microscope ukareba neza uko icyatsi giteye usanga amabara akigize atari icyatsi kibisi nk’uko bigaragarira  amaso. Buri karemangingo fatizo k’ikimera(plant) ubundi  kaba kabonerana(transparent), n’ubwo bwose buri kamwe kaba gafite uduce tubarirwa hagati ya 50 na 100 dusa n’icyatsi(green color). Utu duce nitwo bita chloroplasts ari natwo dukorerwamo photosynthesis.

Muri chloroplasts niho habamo uduce dusa n’icyatsi kibisi twitwa chlorophylls dukorana n’imirasire y’izuba iyo hakorwa photosynthesis.

Chroloplasts zibitsemo udufuka duto natwo dufite utundi duto bita thylacoïds. Kugeza aha tumaze kubona aho ibara ry’icyatsi ku bimera riba riherereye.

Uduce fatizo twa chlorophylls tuba twirundiye hafi yaza thylacoïds, ariko tuba turi mu matsinda mato abahanga bita photo systems.

Ibimera byinshi biba bifite ubwoko bubiri bya photo systems: PS1(Photo system 1), PS 2(Photo system 2). Ubu bwoko bwombi bukorana hafi kandi mu buryo buhambaye kugira ngo butange photosynthesis.

Iyo igice cyo hejuru cya Thylacoïd giteganye n’urumuri rw’izuba, uduce fatizo twa photo system 2 twakira kandi tukabika ingufu zitanzwe n’urwo rumuri. Haba PS 1 cyangwa PS 2 buri imwe yakira ibara ry’urumuri ikeneye kugira ngo ikore akazi kayo.

PS 1 ikunda ibara ry’umutuku. Kuko mu rumuri habamo amabara menshi, usanga hari ayo ikimera kibika kugira ngo akigirire akamaro, hakaba n’irindi bara rimwe ikimera kidakenera ariryo icyatsi kibisi(green color).

Kubera ko ikimera kidakeneye iri bara, kirisohora hanze ku karubanda, maze twe, abantu n’inyamaswa zimwe na zimwe cyane cyane izirisha, tukabona ko ikimera gisa n’icyatsi.

Ibyuma bifotora nabyo bibasha kubona iri bara kuko ababikoze bakurikije uko ijisho ry’umuntu rikora.

Mu yandi magambo, ibimera nibyo bituma tubona uko imirambi idukikije isa bitewe n’amabara y’urumuri biba bikeneye mu mikorere n’imikurire yabyo.

Tugarutse gato muri Chloroplast, tubona ko ingufu z’urumuri rutukura zoherezwa muri twa duce fatizo dufite akabara k’icyatsi bita chlorophylls.

Iyo kamwe muru utu duce kamaze kwakira  urumuri rwinshi mu rugero ruhagije,  tugenzi twako turakajugunya kagasamirwa hejuru n’akandi kakikorera kakagashyira thylacoïde.

Uko buri kamwe kamwe gakomeza gutemberana za ngufu z’urumuri kazishyira thylacoïds zitandukanye, ni nako izi ngufu zigenda zisigara kuri buri gace kazikeneye.

Iyo agace runaka ingufu zako zishize burundu kubera akazi kaba kakoze, kisubirira muri PS 1, kakongera  kwisuganya no kubika izindi ngufu .

Mu by’ukuri photosynthesis irahambaye cyane ku buryo abahanga bamara imyaka biga uko buri gace kayigiramo uruhare gakora. Mu ijoro nabwo irakora.

Dushingiye ku bintu bike tumaze kubona haruguru, twakwemeza ko kugira ngo tubone ko  ikimera gifite ibara ry’icyatsi, biterwa n’uko iri bara ariryo ikimera kiba kidashaka, hanyuma kikarisohora hanze, tukaribona n’amaso yacu.

Andi mabara arimo iroza, umutuku, ubururu n’ayandi aguma imbere mu kibabi bityo ntaboneke ariko nayo atuma ikibabi gitinda kuma iyo ari mu gihe cy’impeshyi.

Source: Réveillez –Vous,  Mutarama 1997

NIZEYIMANA Jean Pierre

UM– USEKE.RW