Noob qhia - dab tsi yog hais tias? lub ntsiab txhais

Yuav ua li cas yog qhov qhia ntawm cov noob? Yuav ua li cas yog nws lub luag hauj lwm? Yuav ua li cas puas muaj tus mechanism ntawm noob qhia? Yuav ua li cas yog lub zeem muag nws yuav qhib ua ntej peb? Yuav ua li cas yog cov kev cai ntawm noob qhia nyob rau hauv eukaryotes thiab prokaryotes? Ntawm no yog ib tug luv luv daim ntawv teev cov lus nug uas yuav raug hais los ntwm nyob rau hauv no tsab xov xwm.

lus qhia dav dav

Noob qhia - yog cov txheej txheem lub npe hloov lwm lub tsev ntawm kev tshuaj ntsuam genetic ntaub ntawv los ntawm DNA ntawm RNA rau cov nqaijrog thiab polypeptides. Cia ua ib tug me me digression to taub. Yuav ua li cas yog noob? Qhov no linear DNA polymers uas muaj kev cob cog los ntawm ib tug ntev saw. Siv ntawm cov protein uas lawv tsim chromatin chromosome. Yog hais tias peb tham txog ib tug neeg, ces peb muaj plaub caug-rau. Lawv nyob txog 50 000-10 000 noob thiab 3.1 billion puag officers. Yuav ua li cas yog coj no? Qhov ntev ntawm lub seem uas ua hauj lwm yog ua, yog qhia nyob rau hauv lub phav phav thiab lab ntawm nucleotides. Ib tug chromosome muaj txog 2000-5000 noob. Nyob rau hauv ib tug sib txawv dog dig nqe lus - txog li 130 lab puag officers. Tab sis qhov no tsuas yog ib tug heev ntxhib kwv yees, uas yog xav paub ntau los yog tsawg dua muaj tseeb rau cov loj sequences. Yog hais tias koj ua hauj lwm tshaj luv luv mus, qhov ratio yuav ua txhaum. Tsis tas li ntawd nyob rau hauv no pem teb yuav cuam tshuam rau lub cev, nyob rau hauv uas lub chaw ua hauj lwm yog nqa tawm cov ntaub ntawv uas.

Hais txog noob

Lawv muaj feem ntau varied ntev. Ntawm no, piv txwv li, globin - yog 1500 nucleotides. Ib tug dystrophin - rau ntau li ntau raws li 2 lab! Lawv cis ntxawg hais tej zaum yuav raug muab tshem ntawm cov noob rau ib tug txiav txim deb. Yog li, nyob rau hauv globin lawv yog ntawm ib tug deb ntawm 50 thiab 30 nucleotides nyob rau hauv tysyach 5'- thiab 3'-kev taw qhia, ntsig txog. Lub xub ntiag ntawm xws li ib lub koom haum ho complicates peb txhais ntawm ib thaj tsam ntawm lawv. Tsis tas li ntawd, cov noob muaj ib tug tseem ceeb npaum li cas ntawm vysokopovtoryayuschihsya zaj haumxeeb dej num uas peb muaj tsis tau to taub.

Yuav kom to taub lawv cov qauv ib tug yuav xav txog tej yam uas 46 chromosomes yog cais tagnrho, nyob rau hauv cov ntaub ntawv uas yog khaws cia. Lawv hoob kawm rau hauv 23 officers. Ib tug ntawm ob tug hais yog pub los ntawm ib tug niam txiv. "Ntawv nyeem," uas yog nyob rau hauv "tagnrho" pheej "rov nyeem" txhiab ntau tiam, uas theem nyob rau hauv ib tug ntau ntawm teeb meem thiab cov kev hloov (hu ua change). Thiab lawv muaj tag nrho yog pub los ntawm cov offspring. Tam sim no muaj txaus theoretical ntaub ntawv mus pib nrog lub fact tias ib tug noob qhia manifests. Qhov tseeb yog lub ntsiab lub ntsiab lus ntawm qhov tsab xov xwm.

Lub hom phiaj ntawm operon

Nws yog raws li nyob rau hauv kev tshuaj ntsuam genetic kev tshawb fawb, β-galactosidase induction, uas koom nyob rau hauv lub hydrolytic cleavage ntawm lactose. Nws twb formulated los ntawm Jacques Monod thiab Fransua Zhakobom. Qhov no kev tshawb xav piav txog cov mechanism rau kev tswj cov synthesis ntawm cov nqaijrog nyob rau hauv prokaryotes. Tsis tas li ntawd ua si ib qho tseem ceeb luag hauj lwm thiab transcription. Qhov kev tshawb xav yog hais tias lub noob yog cov nqaijrog uas feem zoo txog rau metabolic dab, yog feem ntau grouped ua ke. Lawv tsim structural units hu ua operons. Lawv tseem ceeb yog tias tag nrho cov noob uas yog ib feem ntawm nws, hais nyob rau hauv unison. Nyob rau hauv lwm yam lus, lawv yuav tsum tau transcribed, los yog tsis muaj ntawm lawv muaj peev xwm yuav "nyeem". Nyob rau hauv xws li mob, lub operon yog nquag los passive. noob qhia theem yuav raug hloov yog hais tias muaj yog ib tug txheej ntawm ib tug neeg hais.

Induction ntawm protein synthesis

Wb xav txog tej yam uas peb muaj ib tug cell uas nyob rau hauv nws cov kev loj hlob raws li ib tug qhov chaw ntawm carbon siv qabzib. Yog hais tias nws yuav hloov rau lub disaccharide lactose, nyob rau hauv ib tug ob peb feeb koj yuav ua tau kev ruaj ntseg hais tias nws tau yoog mus rau tej yam kev mob uas tau hloov lawm. Tias muaj ib tug piav qhia: lub cell tau khiav lag luam ob qhov chaw ntawm kev loj hlob, tab sis ib tug ntawm lawv yog tsim. Yog li ntawd, muaj ib tug "pom" rau ib tug tshuaj compound fabricable. Tab sis yog hais tias nws yog ploj thiab hloov los ntawm lub zoo nkaus li lactose, lub luag hauj lwm RNA polymerase yog tshuab txais thiab pib pheev nws cov cawv rau zus tau tej cov kev kawm protein. Nws yog ntau tshaj ib tug kev tshawb xav, tab sis tam sim no wb tham txog yuav ua li cas lub sij noob qhia no tshwm sim. Qhov no yog heev exciting.

Lub koom haum ntawm chromatin

Khoom ntawm no cov pawg lus yog ib tug qauv ntawm differentiated hlwb ntawm ib tug multicellular kab mob. Lub nuclei chromatin stacked li ntawd xwb ib tug me me transcription ntawm lub genome yog muaj (txog 1%). Tab sis nyob rau hauv cov kev phem ntawm no, ua tsaug rau lub xovtooj ntawm ntau haiv neeg thiab complexity ntawm cov txheej txheem noj qhov chaw nyob rau hauv lawv peb muaj feem xyuam rau lawv. Thaum lub caij, rau tus neeg nws yog muaj nyob rau tej ib feem nyob rau hauv lub koom haum ntawm chromatin:

1. Hloov tus naj npawb ntawm cov yam ntxwv noob.
2. Nraaj Hour qhov sib txawv qhov chaw hauv lub code.
3. Yaj lub noob nyob rau hauv lub chromosomes.
4. Ua hloov thiab tsim polypeptide chains.

Txawm li cas los, npaum qhia ntawm lub hom phiaj noob yog tiav los ntawm nruj mas technology. Tsis muaj teeb meem dab tsi ua hauj lwm yog ua, txawm yog hais tias tus xyaum ua tej yam mus rau ib tug me ntsis kab mob no. Qhov loj tshaj plaws - yog lo rau lub hom phiaj kos mus txog los ntawm cov kev pab.

Hloov tus naj npawb ntawm cov noob

Yuav ua li cas yuav no yuav siv? Cia peb xav txog tej yam uas peb xav nyob rau hauv cov nyhuv rau noob qhia. Raws li ib tsab peb coj cov ntaub ntawv uas eukaryote. Nws tau siab plasticity, peb thiaj li ua raws li nram no cov kev hloov:

1. Yuav kom nce lub xov tooj ntawm cov noob. Nws yog siv nyob rau hauv tus neeg mob qhov twg nws yog tsim nyog hais tias lub cev muaj zog lub synthesis ntawm ib tug tej yam khoom. Nyob rau hauv xws li ib tug mob yog amplified muaj ntau pab tau cov ntsiab ntawm cov tib neeg genome (e.g., rRNA, tRNA, histones, thiab thiaj li nyob). Tej qhov chaw yuav muaj tandem nyob rau hauv lub chromosomes, thiab txawm mus tshaj li lawv nyob rau hauv tus nqi ntawm 100 txhiab rau 1 lab puag officers. Cia saib ib tug ua daim ntawv thov. Txaus siab rau peb yog qhov metallothionein noob. Nws protein cov khoom yuav khi co heavy li zinc, cadmium, mercury thiab tooj liab thiab, ntsig txog, los tiv thaiv lub cev los ntawm lom lawv. Nws ua kom muaj peev xwm yuav pab tau rau cov neeg uas ua hauj lwm nyob rau hauv tsis zoo tej yam kev mob. Yog hais tias ib tug neeg muaj ib tug muaj zog concentration ntawm hnyav hlau yav tas los hais, lub noob ua kom tshwm sim maj mam txiav.
2. Txo tus xov tooj ntawm noob. Nws yog tsis tshua muaj siv txoj kev cai. Tiam sis ntawm no ib yam nkaus thiab muaj cov piv txwv. Ib qho ntawm feem nto moo - nws yog cov ntshav liab. Thaum lawv paub tab, cov tub ntxhais collapses thiab cov cab kuj loses nws genome. Xws li ib tug txheej txheem ntawm maturation thiab kuaj lymphocytes thiab ntshav hlwb, ntau yam clones uas tau tsim secreted ntaub ntawv ntawm immunoglobulins.

noob rearrangement

Tsis tas li ntawd ib qho tseem ceeb yog cov tau mus thiab combining cov khoom uas nws muaj peev xwm sawv ntawm transcription thiab replication. Qhov no yog hu ua kev tshuaj ntsuam genetic recombination. Los ntawm dab tsi mechanisms nws puas tau? Cia peb xav txog cov lus teb rau lo lus nug no nyob rau hauv lub antibody piv txwv. Lawv yog tsim los ntawm B-lymphocytes, uas yuav mus rau ib co zoo ntawm ib tug tej clone. Thiab nyob rau hauv cov ntaub ntawv ntawm kev sib cuag nrog lub cev ntawm lub antigen uas tus antibody yog complementary muaj tus nquag site ntawm txuas li cas rau tom ntej loj hlob ntawm lub hlwb. Yog vim li cas yog nws hais tias tus tib neeg lub cev muaj peev xwm los tsim ib tug ntau yam ntawm cov nqaijrog? Qhov no yog ua tau los ntawm recombination thiab Somatic change. Tab sis nws yuav yog ib tug tshwm sim ntawm tus txiv neej-kev hloov pauv nyob rau hauv lub DNA qauv.

hloov RNA

Noob qhia - yog tus txheej txheem uas plays ib tug tseem ceeb luag hauj lwm ribonucleic acid. Yog hais tias peb xav txog qhov mRNA yog tsim nyog los nco ntsoov tias tom qab lub transcription thawj qauv tej zaum yuav txawv. Cov kab sab ntawm nucleotides nyob rau hauv lub noob ntawm tib. Tab sis nyob rau hauv txawv nqaij mRNA yuav tshwm sim hloov, insertions, los yog tsuas yog tsis yuav tshwm sim khub niam txiv. Raws li ib qho piv txwv los ntawm qhov yuav ua tau apoprotein B, generated nyob rau hauv lub hlwb ntawm cov hnyuv thiab daim siab. Yuav ua li cas yog editing ib qhov txawv? Cov version ua los ntawm cov hnyuv, muaj 2152 amino acids. Whereas lub siab cov ntsiab lus version boasts 4563 balances! Thiab nyob rau hauv cov kev phem ntawm no sib txawv, peb muaj raws nraim li apoprotein B.

Cov kev hloov nyob rau hauv mRNA stability

Peb muaj yuav luag tuaj rau lub xaus hais tias nws twb tau mus ua nyob rau hauv cov nqaijrog thiab polypeptides. Tab sis cia fim nws tsis tau saib yuav ua li cas yuav tsau mRNA stability. Ua li no, chiv nws yuav tsum tawm hauv lub nucleus thiab tau tawm ntawm lub cytoplasm. Qhov no yog ua tiav dhau ntawm lub uas twb muaj lawm pores. Ib tug loj tus naj npawb ntawm mRNA yog cleaved los ntawm nucleases. Cov uas khiav no txoj hmoo, Teacher ceg nrog proteins. Lub neej ntawm eukaryotic mRNA txawv tshaj ib tug ntau yam (txog li ob peb hnub). Yog hais tias tswj mRNA, ces nyob rau ib taag nqi yuav pom tias lub zog naj npawb ntawm cov tshiab khiv tsim protein cov khoom. noob qhia theem nyob rau hauv cov ntaub ntawv no tsis hloov, tab sis, tseem ceeb tshaj mas, lub cev yuav ua hauj lwm nrog ntau dua efficiency. Siv molecular biology uas hom kev kawm, qhov kawg khoom yuav cim, uas yuav muaj ib tug tseem ceeb lub neej. Yog li, piv txwv li, tau los mus tsim ib tug β-globin ua tau hauj lwm txog kaum teev (qhov no yog heev npaum li cas rau nws).

txheej txheem ceev

Qhov ntawd yog suav tias yog nyob rau hauv general noob qhia system. Tam sim no nws tseem tsuas los pab cov muaj ntaub ntawv, cov kev txawj ntse ntawm yuav ua li cas ceev cov txheej txheem, raws li zoo raws li ntev-lived proteins. Wb hais tias tswj ntawm noob qhia yuav tuav. Nws yuav tsum tau muab sau tseg tias cov nyhuv rau tus nqi yog tsis suav hais tias yog thawj txoj kev cai muaj ntau haiv neeg thiab kom muaj nuj nqis ntawm cov protein cov khoom. Txawm tias nws hloov nyob rau hauv thiaj li yuav ua tau lub hom phiaj no yog tseem siv. Raws li ib qho piv txwv rau hauv lub synthesis ntawm ib tug protein cov khoom nyob rau hauv reticulocytes. Hematopoietic cell ntau yam zoo nyob rau theem deprived ntawm nucleus (thiab chaw pib lub DNA). Cov theem ntawm kev noob qhia kev cai nyob rau hauv kev ua nyob rau ib co zoo ntawm kev twb kev txuas possibilities rau koom feem xyuam rau txoj kev muaj dab.

Lub caij ntawm

Thaum ib tug protein yog tsim, lub sij hawm thaum lub sij hawm uas nws yuav nyob nyob rau hauv lub protease. Muaj tsis tau hu ua raws nraim li sai tau, vim hais tias nyob rau hauv cov ntaub ntawv no yog hom twg los ntawm ib tug ob peb teev mus rau ib tug ob peb xyoos. proteolysis ceev mas nws txawv lug, nyob ntawm seb dab tsi cell nws yog. Enzymes uas yuav catalyze dab yuav sai sai "siv." Vim li no, lawv kuj tsim los ntawm lub cev nyob rau hauv loj qhov ntau. Tsis tas li ntawd nyob rau hauv protein lub neej yuav feem xyuam rau physiological lub xeev ntawm lub cev. Tsis tas li ntawd, yog hais tias tus puas khoom tau raug tsim, nws yuav tsum tau sai sai tshem tawm cov kev tiv thaiv system. Yog li, peb yuav confidently hais tias yog peb muaj peev xwm qhia - qhov no yog qhov txheej txheem lub neej tau nyob rau hauv cov kev kuaj.

xaus

Qhov no cheeb tsam yog heev pheej. Piv txwv li, cov kev qhia ntawm txawv teb chaws noob yuav pab tau los kho raws roj ntsha cov kab mob, thiab tshem tawm tej yam tsis zoo hloov. Txawm tias muaj cov paub nws kim heev nyob rau hauv cov kev kawm, peb yuav confidently hais tias tib neeg yog tseem tsuas yog nyob rau hauv lub heev thaum pib. Genetic engineering xwb nyuam qhuav kawm faib qhov tsim nyog qhov chaw ntawm nucleotides. 20 xyoo dhau los muaj ib tug ntawm cov loj tshaj txheej xwm ntawm no science - twb tsim cov minyuam cov yaj. Tam sim no, kev tshawb fawb yog ua rau tib neeg embryos. Peb yuav hais nrog cog qoob loo uas peb muaj nyob rau ntawm lub chaw pib ntawm lub neej yav tom ntej, qhov twg muaj tsis muaj cov kab mob thiab muaj sia nyuaj siab. Tab sis ua ntej peb paub peb tus kheej muaj, koj yuav tsum tau zoo heev ua hauj lwm rau cov kev pab ntawm txoj kev vam meej.