Gene ibinzana - yintoni leyo? le nkcazelo

Yintoni ibinzana ye zofuzo? Yintoni indima yalo? njani indlela sofuzo nkulumo? Liyintoni ithemba wakuvulela phambi kwethu? Njani na ummiselo gene kwebinzana eukaryotes kunye prokaryotes? Nalu uluhlu elifutshane imibuzo eza kuqwalaselwa kweli nqaku.

ulwazi jikelele

Gene Expression - i transfer inkqubo igama ulwazi yemfuza ukusuka DNA nge RNA kwiiproteni kunye polypeptides. Masenze ukuqonda kuphambuko encinane. Yintoni yemfuza? Oku Iipholima DNA yomgama ukuba idityaniswe kwitsheyini elide. Ukusetyenziswa kwiproteni zakha chromatin chromosome. Xa sincokola ngayo umntu, ngoko thina sibe emashumi mane anesithandathu. Bona ekumgama omalunga 50 000-10 000 genes and 3.1 billion izibini esisiseko. sikhokelwa njani apha? Ubude kumacandelo apho umsebenzi owenziwayo, kuboniswe kule zamawaka ezigidi nucleotides. Enye chromosome iqulethe malunga 2000-5000 yemfuza. In a magama ngandlel eyahlukileyo - malunga 130 million ngababini esisiseko. Kodwa ke loo nto uqikelelo ziingqikelelo kuphela, nto leyo ngaphezulu okanye ngaphantsi yinyaniso ulandelelwano ezinkulu. Ukuba usebenza phezu imigama emifutshane, umlinganiselo iyolala. Kwakhona kule phantsi zingachaphazela umzimba, apho umsebenzi wenziwe eziphathekayo.

malunga zofuzo

Baye ubude kakhulu ezahlukahlukeneyo. Apha, umzekelo, globin - ngu 1500 nucleotides. A dystrophin - kuba kangangoko 2 million! izinto zabo kaKishe regulatory ingasuswa ukusuka sofuzo kumgama elide. Ngenxa yoko, xa globin baba kumgama 50 no-30 nucleotides e tysyach 5'- nolwalathiso-3', ngokulandelelana kwazo. Ubukho kwalo mbutho nzima kakhulu inkcazelo yethu kwemida phakathi kwabo. Kwakhona, izakhi iqulathe isixa esikhulu vysokopovtoryayuschihsya ngokulandelelanisa uxanduva ezisebenzayo esiye okwangoku kakuhle.

Ukuze siqonde ahlelwe umntu ukucinga ukuba 46 zofuzo na imiqulu, apho ulwazi egcinwe. Bona zib 23 ngababini. Enye zinto zimbini njengelifa evela kumzali. "Umbhalo," nto leyo "imithamo" ngokuphindaphindiweyo "re funda-" amawaka ngezizukulwana, nto leyo izisa xa kukho ezininzi iimpazamo kunye notshintsho (ebizwa ngokuba zofuzo). Kwaye bonke esasulela inzalo. Ngoku kukho iinkcukacha ezaneleyo kuphela ukuqalisa ukujongana into yokuba ibinzana gene ubonisa. Le nyaniso isihloko iphambili kweli nqaku.

Imfundiso operon

Oku kusekelwe kwizifundo yemfuza, β-galactosidase induction, leyo yathatha inxaxheba cleavage hydrolytic of lactose. It laliqulunqwe uJacques Monod kunye Fransua Zhakobom. Le mbono lichaza indlela lokulawula Yindibanisela iiproteni prokaryotes. Kwakhona zidlala indima ebalulekileyo kunye nokubhalwa. Le mbono ukuba izakhi ziiproteni abanemfundo ngokusondeleyo ezinxulumene iinkqubo pathways, badla nganxanye. Bona Ukuseka iiyunithi noshowo ebizwa operons. ukubaluleka kwabo kukuba zonke zofuzo abakuyo, va ngazwinye. Ngamanye amazwi, ukuba unako amagama, okanye namnye kubo kunokuba "funda". Kwiimeko ezinjalo, i operon luyasebenza okanye kwisixando sokwenziwa. inqanaba elithi gene oku kungatshintshwa kuphela xa kukho iseti lweziqalelo ngamnye.

KuFacebook protein yokuqaphela

Masenze ngathi ukuba abe neselula apho ekukhuleni kwayo njengomthombo lokusetyenziswa carbon glucose. Ukuba zaba lactose disaccharide, kwimizuzu embalwa unako olukhuselekileyo ukuba liye lakwazi ukuzivumelanisa iimeko zitshintshile. Ukuba kukho ingcaciso: iseli unako ukusebenza zombini imvelaphi ukukhula, kodwa enye yazo efanelekileyo. Ngoko ke, kukho "emehlweni" ukuya fabricable imichiza esimbaxa. Kodwa ukuba ilahlekile indawo yi eli lactose, i-RNA polymerase onoxanduva isebenza kwaye iqalisa ukuba sizibhokoxe kwifuthe lazo ekwenziweni kwiproteni efunekayo. Ungaphezulu ithiyori, kodwa ngoku makhe sithethe ngendlela kwenzeka lezakhi ibinzana elililo. Le nto imnandi kakhulu.

Umbutho we chromatin

Izinto yalo mhlathi ingumzekelo iiseli umahluko we omzimba multicellular. Eziba chromatin elibhalwe ngokuqhelekileyo ukuze kuphela ukukhuphela encinane genome iyafumaneka (malunga-1%). Kodwa nangona oku, wabulela Iseli iyantlukwano nokuntsonkotha iinkqubo ezenzekayo kubo sikwazi nempembelelo kuzo. Okwangoku, kuba umntu iyafumaneka ukuba futhe kwi lombutho chromatin:

1. Ukutshintsha inani yemfuza zezakhiwo.
2. Eyiyo ukubhala iindawo ezahlukeneyo ikhowudi.
3. Yakhiwe zofuzo kwi zofuzo.
4. Yenza ukuguqulwa nezidanga polypeptide kuhlelwe.

Noko ke, amazwi ngobuchule gene ekujoliswe kwenziwa ngobugcisa engqongqo yonamathelo. Enoba yintoni umsebenzi owenziwayo, nokuba olu lingelo luya yintsholongwane encinane. Eyona nto ibalulekileyo - kukuba ukunamathela kwisicwangciso ebesiqulunqwe yi kolo ngenelelo.

Ukutshintsha inani zofuzo

oku kwenziwa njani? Makhe sithi sinomdla ifuthe gene elithi na. Njengoko umatshini senza eukaryote eziphathekayo. Uye plasticity phezulu, singakwazi ke ukwenza utshintsho zilandelayo:

1. Ukwandisa inani yemfuza. Oku kusetyenziswa kwiimeko apho kuyimfuneko ukuba umzimba iwanyusile Yindibanisela imveliso ethile. Zikwimeko ziyanyuswa izinto ezininzi luncedo zofuzo yabantu (umz, rRNA, tRNA, histones, njalo njalo). iziza enjalo ingaba ngokubambisana phakathi zofuzo, yaye uye ngaphaya kubo mali ka-100 lamawaka ezigidi-1 kwisiseko ngababini. Makhe sijonge ukuba zenziwe ngokuphathekayo. Inzala kuthi lezakhi metallothionein. imveliso yawo protein Unga bophelela iintsimbi ezinzima ezifana zinc, isiqalelo esithambileyo esimhlophe, mercury nobhedu, ngokulandelelana, ukukhusela umzimba yingozi kubo. ukusebenza kwayo kunokubaluncedo kubantu abasebenza phantsi kweemeko engakhuselekanga. Ukuba umntu kukho i ndzo ukwanda zesinyithi enzima okhankanywe ngaphambili, ukuqalisa gene lwenzeka kancinci ngokuzenzekelayo.
2. Ukunciphisa inani yemfuza. Oku kunqabile kusetyenziswa indlela ummiselo. Kodwa apha kakhulu kukho imizekelo. Enye edumileyo - kuba iiseli ezibomvu. Xa ukhula, undoqo siyabutyaka kunye nophethe ulahlekelwa ufuzo yayo. Loo inkqubo nokwanda lymphocyte uvavanyo kunye neeseli plasma, clones ezahlukahlukeneyo ukuba kuhlelwe iindlela immunoglobulins secreted.

gene ngokutsha

Enye into ebalulekileyo ithuba ihamba kunye edibanisa izinto ngalo ikwazi umbhalo kanye ukuphindaphindeka. Le nkqubo ibizwa ngokuba recombination yemfuza. Ziziphi iindlela kusenokwenzeka? Makhe sihlolisise impendulo yalo mbuzo kule umzekelo unalo. Zidalwa yi B-lymphocyte, ziphantsi uhlobo oluthile clone ethile. Kwaye xa wadibana umzimba iantigens kuyo izoba Incedisa kwisayithi esebenzayo sothimbo ntoni ukwanda elandelayo iiseli. Kutheni na, ukuba umzimba womntu uyakwazi ukwenza iintlobo iiprotheni? Oku kwenziwa kwenzeka ngenxa recombination kunye zofuzo somatic. Kodwa ingaba ngenxa yeenguqu ngumntu-senziwe kubume DNA.

utshintsho RNA

Gene Expression - yinkqubo apho lidlala indima ebalulekileyo ribonucleic acid. Ukuba siqwalasela mRNA kubalulekile ukuqaphela ukuba emva kokuba isakhiwo ukhutshelo zaseprayimari ungahluka. Ngokulandelelana nucleotides kwi zofuzo efanayo. Kodwa zomzimba ezahlukeneyo mRNA angavela kwabadlali, afakwa kwifayili, okanye nje ukulahlekelwa liya kwenzeka izibini. Njengoko umzekelo uhlobo kunokukhokelela apoprotein B, efunyenwe kwiiseli emathunjini amancinci wesibindi. Yintoni uhlela umahluko? Inguqulelo yenziweyo emathunjini, iye 2152 acid. Nangona umxholo isibindi uguqulelo inama 4563 ngesikali! Kwaye nangona lo mahluko, siye ngqo apoprotein B.

Utshintsho ku nokuzinza mRNA

phantse Siye ukuza kwisigqibo ukuba kungenzeka ntoni iiprothini kunye polypeptides. Kodwa nantsi eyona nyaniso kodwa khangela uzinzo mRNA ingalungiswa njani. Ukuze wenze oku, ekuqaleni kufuneka izishiye ngumongo uphume le icytoplasm. Oku kufezwa pores ezikhoyo. Inani elikhulu mRNA into isisihla yi nucleases. Abo abasindileyo kule ngxaki, ukucwangcisa izakhiwo kunye neeproteni. Yobomi mRNA eukaryotic kuyahlukahlukana kuthotho (iintsuku ezimbalwa). Ukuba lagxila mRNA, ngoko ngeqondo ezinzileyo inokubonakalisa ukuba kwandiswe inani entsha imveliso protein kwakheka. gene level Amazwi kulo mzekelo ayitshintshi, kodwa, okona kubaluleke kakhulu, umzimba uya kusebenza ngempumelelo enkulu. Ukusebenzisa ubuchule ezinto eziphilayo, imveliso yokugqibela unako iibhakhowudi, nto leyo eya kuba ubomi ebalulekileyo. Ngoko ke, umzekelo, unako ukwenza β-globin esebenza malunga ezilishumi iiyure (oku kakhulu kuyo).

inkqubo speed

Oko ngazo kwinkqubo gene ibinzana jikelele. Ngoku uhlala kuphela ukongeza iinkcukacha ezikhoyo, ulwazi ngendlela nkqi iinkqubo, kwakunye iiproteni ixesha elide. Masithi liya kubamba ukuba ulawulo sofuzo nkulumo. Kufuneka kuqatshelwe ukuba ukusebenza ngomhla umlinganiselo akujongwa indlela ephambili kumgaqo iyantlukwano kunye nobungakanani imveliso protini. Nangona lutshintsho ukuze kuphunyezwe le njongo isasetyenziswa nangoku. Njengoko i umzekelo Yindibanisela imveliso iiprothini reticulocytes. Hematopoietic cell umahluko kumgangatho anqunyulwe isiqalo (yaye ngenxa yoko i-DNA). Amanqanaba yommiselo ibinzana sofuzo ngokubanzi zakhiwa kuxhomekeke ethile uhlobo lonxibelelwano ezinokwenzeka ukuba nefuthe elibonakalayo neenkqubo eziqhubekayo.

Ubude

Xa iproteni iya kuhlanganiswa, ixesha ngexesha apho uya kuphila kuxhomekeke protease. Akukho ayikwazi ngokuba kanye kangangoko kunokwenzeka, kuba kulo mzekelo ujongene kwiiyure ezimbalwa ukuya eminyakeni embalwa. Isantya proteolysis iyahluka kakhulu, kuxhomekeke iseli na. Enzayim na catalyze iinkqubo badla ngokukhawuleza "kusetyenziswa." Ngenxa yoko, nazo zidalwe yi umzimba kukuninzi. Kwakhona kwi lokudla protein zinganefuthe imeko komzimba umzimba. Kwakhona, ukuba imveliso alusebenzi sele yenziwe, uya ngokukhawuleza kupheliswa inkqubo olukhuselayo. Ngenxa yoko, nathi ngokuzithemba ukuba kuphela into atshele - oku ke lokudla umgangatho afunyenwe elebhu.

isiphelo

Le ndawo mbiso kakhulu. Umzekelo, ibinzana ingqubana amazwe kunokunceda ukunyanga izifo ilifa, kunye nokuphelisa wezakhi elibi. Nangona kukho ulwazi olunzulu ngalo mbandela, sitsho ngengqiniseko ukuba uluntu nangoku kuphela kanye ekuqaleni. zobunjineli genetic kutshanje nje bafunda kubabela elo iindawo eyimfuneko nucleotides. kwiminyaka engama-20 eyadlulayo kwakukho enye iziganeko ezinkulu zalo inzululwazi - wadalwa Dolly izimvu. Ngoku, uphando luqhutywa kwi ziimbumba. Singatsho ngokuzithemba ukuba embundwini womnyango wendlu elizayo, apho kungekho izifo nokuxinezeleka nokomzimba. Kodwa ngaphambi kokuba sizifumana khona, kufuneka ube kuhle kakhulu ukusebenza ukuze kungenelwe wempumelelo.