Yintoni i-mitochondria? Isakhiwo kunye nemisebenzi

I-Mitochondria yenye yezona zibalulekileyo ezibalulekileyo zeseli. Kwakhona kuthiwa ngama-chondriosomes. Ezi zi-granular okanye i-filaellesous organelles, eziyingxenye ye-cytoplasm yezityalo nezilwanyana. Babavelisi be-molecule ze-ATP, eziyimfuneko kakhulu kwiinkqubo ezininzi kwiseli.

Yintoni i-mitochondria?

I-Mitochondria yisezantsi yamandla eeseli, imisebenzi yabo isekelwe kwi-oxidation yamacandelo e-organic kunye nokusetyenziswa kwamandla okukhululwa ngexesha lokuchithwa kwee-molecule ze-ATP. I-Biologists ngolwimi olulula libiza ngokuba yindawo yokuvelisa amandla kwiiseli. Ngo-1850 i-mitochondria yafunyanwa ngohlobo lwe-granules kwiimisipha. Inani labo lihluka ngoxhomekeke kwiimeko zokukhula: ziqokelela ngaphezulu kwezo iiseli apho kukho ubuninzi be-oxygen. Oku kwenzeka ngokuqhelekileyo ngemisebenzi yomzimba. Kwizicubu ezinjalo kunqongophala kwamanzi, okuzaliswa yimitochondria.

Ukubonakala kwegama kunye nendawo kwindawo ye-symbiogenesis

Ngomnyaka we-1897, iBend kuqala yazisa ingcamango "ye-mitochondria" ukubonisa isakhiwo esine-granular and filamentous kwi- cytoplasm yeeseli. Ngefom kunye nobukhulu, bahlukeneyo: ubukhulu buyi-0.6 μm, ubude buvela ku-1 ukuya ku-11 μm. Kwiimeko ezinqabileyo i-mitochondria ingaba nobukhulu obukhulu kunye nokuhlangana kwamagatsha.

Kwiingcamango ze-symbiogenesis, ingcamango ecacileyo yanikezwa yintoni imitochondria kunye nendlela abavela ngayo kwiiseli. Ithi i-chondriosoma ivela kwinkqubo yokutshatyalaliswa kweebhaktheriya ngamabhaktheriya, iiprokaryothi. Ekubeni abazange bakwazi ukusebenzisa amandla oksijini ukuze bavelise amandla, oku kukuthintela uphuhliso lwabo olupheleleyo, kwaye abaxhasi bangakwazi ukuphuhliswa. Kukho konke ukuziphendukela kwemvelo, ukuxhamla phakathi kwabo kuye kwabavumela ukuba iifengenji zitshintshe iigeni zabo ngoku kwi-eukaryoti. Siyabulela kule nkqubela, i-mitochondria ayisekho iimeko ezizimeleyo. I-pool yabo yemfuyo ayikwazi ukuzaliseka ngokupheleleyo, kuba ivinjiwe ngeenzyme ezikhoyo nasiphi na iseli.

Bahlala phi?

I-Mitochondria igxininiswe kule mimandla ye-cytoplasm, apho kukho isidingo se-ATP. Ngokomzekelo, kwiisisipha zeenthambo zentliziyo zifumaneka kufuphi ne-myofibril, kwaye kwi-spermatozoa zenza i-masking ekhuselekileyo ejikeleze i-axis yesihlunu. Apho bavelisa amandla amaninzi ukuze "umsila" ujikeleze. Yile ndlela umdlwane ehamba ngayo kwiqanda.

Kwiiseli, i-mitochondria entsha yenziwe ngokuhlukana okulula kwezigqeba zangaphambili. Ngelo xesha, lonke ulwazi oluzuze ilifa lugcinwe.

Mitochondria: indlela abajonga ngayo

Ubume be-mitochondria bufana nesilinda. Zivame ukufumaneka kwi-eukaryoti, zihlala kwi-10 ukuya ku-21% yevolumu yeseli. Ubukhulu babo nobubunzima bohluke kwiintlobo ezininzi kwaye banako ukuhluka ngokuxhomekeka kwiimeko, kodwa ububanzi buhlala njalo: 0.5-1 μm. Ukunyakaza kwama-chondriosomes kuxhomekeka apho iiseli zichitha udoti olukhawulezayo lwamandla. Uhanjiswe kwi-cytoplasm, usebenzisa ukuhambisa isakhiwo se-cytoskeleton. Ukutshintshwa kwe-mitochondria, eyahlukileyo ngobukhulu, isebenza ngokwahlukileyo komnye kunye nokunikezela iindawo ezithile ze-cytoplasm, zide kunye ne-branch mitochondria. Bayakwazi ukubonelela ngamaseli ahlukeneyo. Umsebenzi odibeneyo we-chondriosomes awugcinwa kuphela kwizinto eziphilayo, kodwa nakwizinto ezininzi zezilwanyana. Isakhiwo esiyinkimbinkimbi kakhulu se-chondriomas sitholakala kwiimisipha zamathambo ama-mammalian, apho i-chondriosomes enkulu kunazo zonke zihambelana nomnye usebenzisa i-intermithochondrial contact (MMC).

Ziyithuba elincinci phakathi kweembrane eziphambene nemitha. Esi sithuba sinobuninzi be-electron. Ii-MMK ziqhelekileyo kwiiseli zesisu senhliziyo, apho zibopha kunye nama-chondriosomes esebenzayo.

Ukuze siqonde kakuhle umbandela, kufuneka sichaze ngokufutshane ukubaluleka kwe-mitochondria, isakhiwo kunye nemisebenzi yale mibutho.

Zilungiselelwe njani?

Ukuqonda ukuba imitochondria yintoni, kufuneka ukwazi isakhiwo sabo. Lo mthombo ongaqhelekanga wamandla unobumba bhola, kodwa udlalwa rhoqo. Iimbumba ezimbini zifumaneka kufuphi:

• Ngaphandle (elula);
• I-Internal, eyenza ukuphuma kwamaphepha amaqabunga (cristae) kunye namafayili (tubula).

Ukuba awuqwalaselanga ubukhulu kunye nomlo we-mitochondria, isakhiwo kunye nemisebenzi yazo zifana. I-chondriosoma inqunywe iimbumba ezimbini, 6 nm ngobukhulu. I-membrane yangaphandle ye-mitochondria ifana nesitya sokubakhusela kwi-hyaloplasm. Umlenze wangaphakathi ovela ngaphandle uhlukanisa icandelo 11-19 nm ububanzi. Isici esibonakalayo sekhanda elingaphakathi liyakwazi ukukhupha kwi-mitochondria, ithatha uhlobo lwe-crests ephothiweyo.
Isango sangaphakathi se-mitochondria sigcwele umthamo onesakhiwo esilungileyo, apho ngezinye iinkhathi i-filaments kunye ne-granules (15-20 nm) zifunyanwa. Iimpawu zeMatrix zidala i- DNA molecules ze- organelles, kunye ne-granules yamancinci amancinci i-mitochondria ribosomes.

I-synthesis ye-ATP kwisigaba sokuqala senziwa kwi-hyaloplasm. Kule nqanaba, kukho i-oxidation yokuqala ye-substrates okanye i-glucose kwi- acid ye-pyruvic. Ezi nkqubo zihamba ngaphandle kwe-oxygen-anaerobic oxidation. Isigaba esilandelayo sophuhliso lwamandla yi-aerobic oxidation kunye nokuchithwa kwe-ATP, le nqubo ivela kwi-mitochondria yeeseli.

Yenzani i mitochondria?

Imisebenzi ephambili yale nxalenye yile:

• Ukuveliswa kwamandla kwiiseli;

• Ukugcinwa kolwazi oluzuze ngefa kwi-DNA yayo.

Ubukho kwi-mitochondria ye-deoxyribonucleic acid kwakhona kwakhona buqinisekisa ubungqina be-symbiotic of the appearance of these organelles. Kananjalo, ngaphezu komsebenzi oyintloko, babandakanyeka kwi-hormone kunye nama-amino acids.

I-Mitochondrial pathology

Utshintsho olwenzeka kwi-genome ye-mitochondria lukhokelela kwimiphumo ecindezelayo. Umphathiswa wolwazi lomfuzo we-DNA, oludluliselwa kwinzala evela kubazali, kwaye i-genic mitochondrial idluliselwa kuphela kumama. Le nyaniso ichazwa ngokucacileyo: i-cytoplasm kunye ne-chondriosomes edibene kuyo inikwe abantwana kunye ne-ovum yabesifazane, abakhoyo kwi-spermatozoa. Abasetyhini abanalo okungaqhelekanga banokuhambisa isifo se-mitochondrial kwinzala, indoda egulayo ayikho.

Kwiimeko eziqhelekileyo, ii-chondriosomes zinekopi efanayo ye-DNA-homoplasmy. Kwiinguqu ze-genito mitochondrial ziyakwenzeka, ngenxa yokuzibandakanya kweeseli ezinempilo kwaye zatshintshile, i-heteroplasm ibonakala.

Ndiyabulela kumachiza anamhlanje ukuya kutsho, izifo ezingaphezu kwe-200 zithe zachongwa, imbangela yayo yayikuguqulwa kwe-DNA ye-mitochondria. Akuzona zonke iimeko, kodwa ukugcinwa kwezilwanyana kunye nokunyanga izifo ze-mitochondrial ziphelela kakuhle.

Ngoko siqikelele ukuba yiyiphi imitochondria. Njengazo zonke i-organelles, zibaluleke kakhulu kwiseli. Zithathe inxaxheba ngokuthe ngqo kuzo zonke iinkqubo ezifunekayo zamandla.