Txoj kev cai ntawm kev tsim noob neej tau nyiam tib neeg txij li thaum nws thawj zaug pom tseeb tias noob caj noob ces yog ib yam khoom siv ntau dua li qee lub zog siab dua. Cov txiv neej niaj hnub no paub tias cov kab mob muaj peev xwm tsim tau zoo ib yam li lawv tus kheej, thaum cov xeeb ntxwv tau txais cov yam ntxwv tshwj xeeb thiab cov yam ntxwv muaj nyob hauv lawv niam lawv txiv. Kev tsim tawm yog pom tau vim muaj peev xwm hloov cov ntaub ntawv caj ces ntawm ntau tiam neeg.
Txoj Kev: Koj tsis tuaj yeem muaj ntau dhau
Txoj kev cai lij choj ntawm caj ces pib tshawb nrhiav tsis ntev los no xwb. Ib qho tseem ceeb tshaj plaws nyob rau hauv qhov teeb meem no tau ua nyob rau hauv lub xyoo pua xeem, thaum Sutton thiab Boveri coj ib tug tshiab hypothesis rau pej xeem. Nws yog thaum ntawd lawv tau hais tias chromosomes tej zaum muaj cov ntaub ntawv caj ces. Ib me ntsis tom qab, thev naus laus zis tso cai rau kev tshawb fawb tshuaj ntawm chromosome muaj pes tsawg leeg. Nws nthuav tawmlub xub ntiag ntawm tej nucleic tebchaw ntawm cov proteins. Proteins tau dhau los ua qhov muaj nyob hauv ntau hom qauv thiab cov ntsiab lus ntawm cov tshuaj muaj pes tsawg leeg. Tau ntev, cov kws tshawb fawb ntseeg tias nws yog cov proteins uas yog qhov tseem ceeb uas ua kom muaj kev hloov pauv ntawm cov ntaub ntawv caj ces ntawm ntau tiam neeg.
Ntau xyoo ntawm kev tshawb fawb txog cov ncauj lus no tau muab kev nkag siab tshiab rau qhov tseem ceeb ntawm cell DNA. Raws li cov kws tshawb fawb tau nthuav tawm, tsuas yog cov molecules no yog cov khoom siv ntawm cov ntaub ntawv muaj txiaj ntsig. Molecules yog ib feem ntawm chromosome. Niaj hnub no, yuav luag txhua tus ntawm peb cov neeg nyob hauv lub tebchaws uas tau txais kev kawm dav dav, nrog rau cov neeg nyob hauv ntau lub tebchaws, paub zoo txog qhov tseem ceeb ntawm DNA molecules rau ib tug neeg, kev loj hlob ntawm tib neeg lub cev. Ntau tus xav txog qhov tseem ceeb ntawm cov molecules nyob rau hauv cov nqe lus ntawm heredity.
Ntxhais yog kev tshawb fawb
Molecular genetics, uas cuam tshuam nrog kev kawm ntawm cell DNA, muaj lwm lub npe - biochemical. Thaj chaw ntawm kev tshawb fawb no tau tsim los ntawm kev sib tshuam ntawm biochemistry thiab noob caj noob ces. Kev sib koom ua ke kev coj noj coj ua yog thaj chaw tsim khoom ntawm tib neeg kev tshawb fawb, uas tau muab cov kev tshawb fawb hauv zej zog nrog ntau cov ntaub ntawv tseem ceeb uas tsis muaj rau cov neeg koom nrog tsuas yog biochemistry lossis noob caj noob ces. Cov kev sim ua los ntawm cov kws tshaj lij hauv daim teb no suav nrog kev ua haujlwm nrog ntau hom kev ua neej thiab cov kab mob ntawm ntau hom thiab pawg. Cov txiaj ntsig tseem ceeb tshaj plaws tau txais los ntawm cov zej zog kev tshawb fawb yog qhov tshwm sim ntawm kev tshawb fawb ntawm tib neeg cov noob caj noob ces, nrog rau ntau yam.kab mob. Ntawm cov tom kawg, ntawm qhov tseem ceeb tshaj plaws yog Eisheria coli, lambda phages ntawm cov microbes, neurospore crassa fungi thiab Saccharomyces cerevisia.
Genetic bases
Rau lub sijhawm ntev, cov kws tshawb fawb tsis muaj qhov tsis ntseeg txog qhov tseem ceeb ntawm chromosome hauv kev hloov cov ntaub ntawv keeb kwm ntawm ntau tiam neeg. Raws li kev ntsuam xyuas tshwj xeeb tau pom, chromosomes yog tsim los ntawm cov kua qaub, cov proteins. Yog tias koj ua qhov kev sim staining, cov protein yuav raug tso tawm ntawm cov molecule, tab sis NA yuav nyob twj ywm. Cov kws tshawb fawb muaj pov thawj ntau dua uas tso cai rau peb tham txog kev sib sau ntawm cov ntaub ntawv caj ces hauv NK. Nws yog los ntawm lawv cov ntaub ntawv kis tau los ntawm ntau tiam neeg. Cov kab mob tsim los ntawm cov hlwb, cov kab mob uas muaj DNA, tau txais cov ntaub ntawv los ntawm tiam dhau los los ntawm DNA. Qee cov kab mob muaj RNA. Nws yog cov kua qaub no uas yog lub luag haujlwm rau kev xa cov ntaub ntawv. RNA, DNA yog NK, uas yog cov yam ntxwv ntawm cov qauv zoo sib xws, tab sis kuj muaj qhov sib txawv.
Kawm txog lub luag haujlwm ntawm DNA hauv kev tsim noob neej, cov kws tshawb fawb tau pom tias cov molecules ntawm cov kua qaub no muaj plaub hom nitrogen tebchaw thiab deoxyribose. Vim cov ntsiab lus no, cov ntaub ntawv caj ces raug xa mus. Lub molecule muaj purine tshuaj adenine, guanine, pyrimidine ua ke thymine, cytosine. Cov tshuaj molecular txha caj qaum yog qab zib residues alternating nrog phosphoric acid residues. Txhua qhov seem muaj qhov txuas rau cov qauv carbon los ntawm cov suab thaj. Nitrogenous bases txuas rau ntawm ob sab rau qab zib residues.
Npe thiab hnub
Cov kws tshawb fawb,tshawb xyuas biochemical thiab molecular foundations ntawm heredity, lawv muaj peev xwm txheeb xyuas cov yam ntxwv ntawm DNA tsuas yog nyob rau hauv 53rd. Kev sau ntawv ntawm cov ntaub ntawv tshawb fawb tau muab rau Crick, Watson. Lawv tau ua pov thawj tias ib qho DNA coj mus rau hauv tus account cov yam ntxwv tshwj xeeb ntawm kev tsim noob neej. Thaum tsim ib qho qauv, koj yuav tsum nco ntsoov txog qhov sib npaug ntawm qhov chaw thiab muaj peev xwm sib sau ua ke, xa cov ntaub ntawv keeb kwm yav dhau los. Muaj peev xwm, cov molecule tuaj yeem hloov pauv. Chemical Chemical Chemical Chemical Chemical Chemical Chemical Chemical Chemical Cheebtsam, lawv cov kev sib xyaw ua ke, ua ke nrog cov txheej txheem ntawm X-ray diffraction kev tshawb fawb, ua rau nws muaj peev xwm txiav txim siab cov qauv molecular ntawm DNA ua ob lub helix. Nws yog tsim los ntawm ib nrab ntawm antiparallel hom spirals. Cov pob txha qab zib-phosphate yog ntxiv nrog hydrogen bonds.
Hauv kev kawm ntawm lub hauv paus molecular ntawm heredity thiab variability, cov hauj lwm ntawm Chargaff yog qhov tseem ceeb. Tus kws tshawb fawb tau mob siab rau nws tus kheej rau kev kawm txog cov nucleotides tam sim no hauv cov qauv ntawm nucleic acid. Raws li nws tau nthuav tawm, txhua lub ntsiab lus no yog tsim los ntawm nitrogen hauv paus, phosphorus residues, qab zib. Kev sib sau ntawm cov ntsiab lus molar ntawm thymine, adenine tau tshwm sim, qhov zoo sib xws ntawm qhov ntsuas no rau cytosine thiab guanine tau tsim. Nws tau xav tias txhua tus thymine residue muaj ib khub adenine, thiab rau guanine muaj cytosine.
Same but so different
Kawm nucleic acids raws li lub hauv paus ntawm kev tsim noob neej, cov kws tshawb fawb tau txiav txim siab tias DNA belongs rau qeb ntawm polynucleotides tsim los ntawm ntau nucleotides. Qhov feem ntau unpredictable sequences ntawm lub ntsiab nyob rau hauv ib tug saw yog ua tau. Raws li txoj cai, serial ntau haiv neeg tsis muajtxwv. DNA muaj cov yam ntxwv tshwj xeeb uas cuam tshuam nrog kev sib koom ua ke ntawm nws cov khoom, tab sis kev sib koom ua ke tshwm sim raws li kev cai lij choj lom neeg thiab tshuaj lom neeg. Qhov no tso cai rau koj los predefining sequences ntawm txawv chains. Qhov zoo no hu ua complementarity. Nws piav qhia txog lub peev xwm ntawm cov molecule kom ua tiav nws cov qauv.
Thaum kawm txog keeb kwm thiab kev hloov pauv los ntawm DNA, cov kws tshawb fawb pom tias cov strands uas tsim DNA yog cov qauv rau kev tsim cov blocks ntxiv. Rau qhov tshwm sim tshwm sim, lub molecule unwinds. Cov txheej txheem yog nrog los ntawm kev puas tsuaj ntawm hydrogen bonds. Bases cuam tshuam nrog cov khoom sib txuas ntxiv, uas ua rau tsim cov ntawv cog lus tshwj xeeb. Tom qab cov nucleotides raug kho, kev sib txuas ntawm cov molecule tshwm sim, ua rau cov tsos ntawm ib tug tshiab polynucleotide tsim, qhov sib lawv liag ntawm qhov uas yog predetermined los ntawm cov khoom pib. Qhov no yog li cas ob lub molecules zoo tib yam tshwm sim, saturated nrog cov ntaub ntawv zoo tib yam.
Replica: tus lav kev ruaj khov thiab hloov pauv
Piav saum toj no muab ib lub tswv yim ntawm kev siv ntawm heredity thiab variability los ntawm DNA. Cov txheej txheem rov ua dua piav qhia vim li cas DNA muaj nyob hauv txhua lub xov tooj ntawm tes, thaum chromosome yog ib qho organoid tshwj xeeb uas tsim tawm ntau thiab zoo nrog qhov tseeb tshwj xeeb. Hom kev faib tawm tiag tiag no tsis tuaj yeem ua tau kom txog thaum qhov tseeb ntawm ob chav helical complementary qauv ntawm cov molecule tau tsim. Crick, Watson, yav dhau los tau xav tias cov qauv molecular yog dab tsi, tau hloov mus ua yog lawm, txawm hais tias dhau sijhawm cov kws tshawb fawb pib tsis ntseeg qhov tseeb ntawm lawv lub zeem muag ntawm cov txheej txheem rov ua dua. Thaum xub thawj, nws tau ntseeg tias spirals los ntawm ib lub saw hlau tshwm sim ib txhij. Enzymes uas catalyze molecular synthesis nyob rau hauv lub chaw kuaj mob paub tias ua hauj lwm nyob rau hauv ib qho kev taw qhia, uas yog, thawj ib tug saw, ces tus thib ob.
Cov txheej txheem niaj hnub ntawm kev kawm tib neeg kev tsim noob neej tau ua rau nws muaj peev xwm simulate DNA tsis tu ncua. Tus qauv tau tshwm sim hauv 68th. Lub hauv paus rau nws lub tswv yim yog kev sim ua haujlwm siv Eisheria coli. Kev sau ntawv ntawm kev tshawb fawb tau raug xa mus rau Orzaki. Cov kws tshaj lij niaj hnub no muaj cov ntaub ntawv tseeb ntawm cov nuances ntawm kev sib txuas nrog eukaryotes, prokaryotes. Los ntawm cov noob caj noob ces rab rawg, kev loj hlob tshwm sim los ntawm kev tsim cov khoom tawg ua ke los ntawm DNA ligase.
Cov txheej txheem synthesis yog suav tias yog tas mus li. Cov tshuaj tiv thaiv replicate muaj ntau cov proteins. Lub unwinding ntawm lub molecule tshwm sim vim lub enzyme, preservation ntawm lub xeev no yog guaranteed los ntawm lub destabilizing protein, thiab cov synthesis pib los ntawm lub polymerase.
Cov ntaub ntawv tshiab, kev xav tshiab
Siv cov txheej txheem niaj hnub ntawm kev kawm tib neeg caj ces, cov kws tshaj lij tau txheeb xyuas qhov twg qhov yuam kev rov los ntawm. Qhov kev piav qhia tau ua tau thaum cov ntaub ntawv meej txog cov txheej txheem ntawm kev luam cov molecules thiab cov yam ntxwv tshwj xeeb ntawm cov qauv molecular tau dhau los. Cov txheej txheem replication xav tiasdivergence ntawm niam txiv molecules, nrog rau txhua ib nrab ua raws li ib tug matrix rau ib tug tshiab saw. Synthesis yog pom tau hais tias vim hydrogen bonds ntawm lub hauv paus, nrog rau mononucleotide ntsiab ntawm cov khoom ntawm cov txheej txheem metabolic. Txhawm rau tsim cov ntawv cog lus ntawm thiamine, adenine lossis cytosine, guanine, yuav tsum tau hloov cov tshuaj mus rau daim ntawv tautomeric. Nyob rau hauv ib puag ncig dej, txhua qhov sib txuas no muaj nyob hauv ntau hom; lawv tag nrho tautomeric.
Muaj ntau qhov kev xaiv ntau dua thiab tsawg dua. Ib qho tshwj xeeb yog txoj haujlwm ntawm hydrogen atom hauv cov qauv molecular. Yog hais tias cov tshuaj tiv thaiv tshwm sim nrog ib tug tsis tshua muaj variant ntawm daim ntawv tautomeric, nws tshwm sim nyob rau hauv tsim ntawm bonds nrog lub hauv paus tsis ncaj ncees lawm. Lub DNA strand tau txais cov nucleotide tsis raug, qhov sib lawv liag ntawm cov ntsiab lus hloov ruaj khov, kev hloov pauv tshwm sim. Lub tshuab hloov pauv tau piav qhia thawj zaug los ntawm Crick, Watson. Lawv cov lus xaus yog lub hauv paus ntawm lub tswv yim niaj hnub ntawm kev hloov pauv.
RNA nta
Kawm txog lub hauv paus molecular ntawm heredity, cov kws tshawb fawb tsis tuaj yeem tsis quav ntsej qhov tseem ceeb tshaj DNA nucleic acid - RNA. Nws belongs rau pawg ntawm polynucleotides thiab muaj cov qauv zoo sib xws nrog cov uas tau piav ua ntej. Qhov sib txawv tseem ceeb yog kev siv ribose raws li cov seem uas ua raws li lub hauv paus ntawm cov pob txha carbon. Hauv DNA, peb nco qab, lub luag haujlwm no yog ua los ntawm deoxyribose. Qhov thib ob qhov txawv yog tias thymine hloov los ntawm uracil. Cov tshuaj no kuj yog nyob rau hauv chav kawm ntawm pyrimidines.
Kawm txog lub luag haujlwm caj ces ntawm DNA thiab RNA, cov kws tshawb fawb thawj zaug txiav txim siab qhov sib txawv. Qhov sib txawv tsis tseem ceeb hauv cov qauv tshuaj ntawm cov ntsiab lus, tab sis kev kawm ntxiv ntawm cov ncauj lus pom tau tias lawv ua lub luag haujlwm loj. Cov kev sib txawv no kho qhov tseem ceeb ntawm txhua qhov ntawm cov molecules, yog li cov hais polynucleotides tsis hloov ib leeg rau cov kab mob nyob.
Feem ntau RNA yog tsim los ntawm ib txoj hlua, sib txawv ntawm ib qho loj, tab sis feem ntau lawv me dua DNA. Cov kab mob uas muaj RNA muaj nyob rau hauv lawv cov qauv xws li molecules tsim los ntawm ob strands - lawv cov qauv yog ze li sai tau rau DNA. Hauv RNA, cov ntaub ntawv caj ces yog sau thiab dhau ntawm ntau tiam neeg. Lwm cov RNAs tau muab faib ua hom kev ua haujlwm. Lawv yog tsim los ntawm DNA templates. Cov txheej txheem yog catalyzed los ntawm RNA polymerases.
Cov ntaub ntawv thiab keeb kwm
Kev tshawb fawb niaj hnub no, kawm txog cov molecular thiab cytological foundations ntawm heredity, tau txheeb xyuas cov nucleic acids uas yog lub ntsiab ntawm kev tsub zuj zuj ntawm cov ntaub ntawv caj ces - qhov no sib npaug rau txhua yam muaj sia nyob. Hauv ntau hom kev ua neej, DNA ua lub luag haujlwm tseem ceeb. Cov ntaub ntawv sau los ntawm cov molecule yog stabilized los ntawm nucleotide sequences uas yog reproduced thaum lub sij hawm cell faib raws li ib tug unchanged mechanism. Molecular synthesis pib nrog kev koom tes ntawm enzyme Cheebtsam, thaum lub matrix yog ib txwm cov nucleotide saw dhau los, uas yog materially kis ntawm hlwb.
Qee lub sij hawm cov tub ntxhais kawm nyob rau hauv lub moj khaum ntawm biology thiab microbiology tau muab cov kev daws teeb meem ntawm noob caj noob ces rau kev pom kev pom ntawm kev vam khom. Lub hauv paus molecular ntawm heredity nyob rau hauv cov teeb meem no suav hais tias yog txheeb ze rau DNA,zoo li RNA. Nws yuav tsum tau nco ntsoov tias nyob rau hauv cov ntaub ntawv ntawm ib tug molecule uas nws noob caj noob ces yog sau los ntawm RNA los ntawm ib tug helix, cov txheej txheem kev ua me nyuam mus raws li ib txoj kev zoo ib yam li cov uas tau piav ua ntej. Lub template yog RNA nyob rau hauv ib daim ntawv uas yuav replicated. Qhov no tshwm sim nyob rau hauv lub cellular qauv vim yog kis kab mob. Kev nkag siab txog cov txheej txheem no tso cai rau cov kws tshawb fawb los kho qhov tshwm sim ntawm cov noob thiab nthuav cov kev paub txog nws. Classical science to taub cov noob raws li ib chav tsev ntawm cov ntaub ntawv kis tau los ntawm ntau tiam neeg thiab nthuav tawm hauv kev sim ua haujlwm. Cov noob muaj peev xwm ntawm kev hloov pauv, ua ke nrog lwm cov units ntawm tib theem. Lub phenotype uas ib yam kabmob muaj yog piav qhia meej los ntawm cov noob - qhov no yog nws txoj haujlwm tseem ceeb.
Hauv kev tshawb fawb, cov noob raws li lub hauv paus ua haujlwm ntawm kev xeeb tub tau pib suav tias yog ib lub luag haujlwm rau kev sib koom ua ke, kev hloov pauv. Tam sim no, nws paub tseeb tias ob qhov zoo no yog lub luag haujlwm ntawm nucleotide khub uas suav nrog hauv DNA. Tab sis txoj haujlwm yog muab los ntawm nucleotide ib ntus ntawm ntau pua thiab ntau txhiab units uas txiav txim siab cov amino acid protein chains.
Proteins thiab lawv lub luag haujlwm genetic
Nyob rau hauv kev tshawb fawb niaj hnub no, kawm txog kev faib cov noob, cov hauv paus molecular ntawm heredity raug txiav txim siab los ntawm qhov pom ntawm qhov tseem ceeb ntawm cov qauv protein. Txhua yam muaj sia nyob yog ib feem tsim los ntawm cov proteins. Lawv suav hais tias yog ib qho ntawm cov khoom tseem ceeb tshaj plaws. Protein yog ib qho tshwj xeeb amino acid ib ntus uas hloov hauv zos thaummuaj xwm txheej. Feem ntau muaj ob lub kaum os hom amino acids, lwm tus yog tsim los ntawm cov enzymes los ntawm lub ntsiab nees nkaum.
Kev sib txawv ntawm cov protein zoo nyob ntawm cov qauv molecular, cov amino acid polypeptide ib ntus uas tsim cov protein. Cov kev sim tau ua kom pom tseeb tias cov amino acid muaj ib qho kev qhia nruj me ntsis hauv cheeb tsam DNA nucleotide saw. Cov kws tshawb fawb hu nws qhov sib piv ntawm cov ntsiab lus protein thiab nucleic acids. Qhov tshwm sim hu ua colinearity.
DNA nta
Biochemistry thiab noob caj noob ces, uas kawm lub hauv paus molecular ntawm heredity, yog sciences uas tshwj xeeb yog them rau DNA. Cov molecule no yog cais raws li ib tug linear polymer. Cov kev tshawb fawb tau pom tias qhov kev hloov pauv tsuas yog muaj rau cov qauv yog cov kab ke nucleotide. Nws yog lub luag haujlwm rau encoding cov kab ke ntawm cov amino acids hauv cov protein.
YNyob rau hauv eukaryotes, DNA nyob rau hauv lub cell nucleus, thiab protein ntau tsim nyob rau hauv lub cytoplasm. DNA tsis ua lub luag haujlwm ntawm tus qauv rau cov txheej txheem ntawm kev tsim cov protein, uas txhais tau hais tias yuav tsum muaj cov khoom nruab nrab uas yog lub luag haujlwm rau kev thauj cov ntaub ntawv caj ces. Cov kev tshawb fawb tau pom tias lub luag haujlwm raug muab rau RNA template.
Raws li pom los ntawm kev tshawb fawb ua haujlwm rau lub hauv paus molecular ntawm heredity, cov ntaub ntawv raug xa los ntawm DNA mus rau RNA. RNA tuaj yeem nqa cov ntaub ntawv rau cov protein thiab DNA. Cov protein tau txais cov ntaub ntawv los ntawm RNA thiab xa mus rau tib lub qauv. Tsis muaj kev sib txuas ncaj qha ntawm DNA thiab cov proteins.
Txiv neejinfo: this is interesting
Raws li cov haujlwm tshawb fawb tau mob siab rau lub hauv paus molecular ntawm heredity tau pom, cov ntaub ntawv caj ces yog cov ntaub ntawv tsis muaj zog uas pom tau tsuas yog nyob rau hauv lub xub ntiag ntawm lub zog sab nraud thiab cov khoom siv hauv tsev. DNA yog ib qho molecule uas tsis muaj cov peev txheej zoo li no. Lub xovtooj ntawm tes tau txais qhov nws xav tau los ntawm sab nraud los ntawm cov protein, tom qab ntawd kev hloov pauv pib pib. Muaj peb txoj hauv kev qhia txog kev txhawb nqa lub neej. Lawv txuas nrog ib leeg, tab sis ywj siab. Cov ntaub ntawv caj ces yog kis tau los ntawm DNA replication. Cov ntaub ntawv yog encoded los ntawm genome - cov kwj dej no suav tias yog qhov thib ob. Qhov thib peb thiab zaum kawg yog cov khoom noj khoom haus uas niaj hnub nkag mus rau hauv cov qauv cellular los ntawm sab nraud, muab lub zog thiab cov khoom xyaw hauv tsev.
Qhov ntau lub cev tsim kho, ntau lub ntsiab lus ntawm genome. Ib tug ntau yam gene teeb siv cov ntaub ntawv encrypted nyob rau hauv nws los ntawm kev sib koom tes mechanisms. Cov ntaub ntawv nplua nuj ntawm tes txiav txim siab yuav ua li cas siv cov ntaub ntawv thaiv tus kheej. Vim qhov kev ua tau zoo no, lub peev xwm los hloov kho rau cov xwm txheej sab nraud nce. Cov ntaub ntawv sib txawv ntawm cov noob caj noob ces muaj nyob hauv DNA yog lub hauv paus ntawm cov protein synthesis. Genetic tswj ntawm synthesis yog ib txoj kev xav tsim los ntawm Monod thiab Jacob hauv xyoo 1961. Tib lub sijhawm, tus qauv operon tau tshwm sim.
