Trigeminal code thiab haumxeeb chav tsev ntawm caj code

Tus thawj inhabitants ntawm no ntiaj chaw yog yuav muaj heev me ntsis lub neej. Evolutionary kev taw qhia tag nrho cov nyob mus ntawm tom neej ntawm ib tug kab mob rau ib tug muaj kev vam meej adaptation rau cov ib puag ncig tej yam kev mob, txoj kev loj hlob mechanisms ntawm adaptation thiab tseem kis tau tus mob ntawm kev tom ntej tiam. Tsim organic molecules raws li lub hom phiaj tau tso cai lub neej nyob rau lub ntiaj teb kom txais tau ib foothold thiab pib muaj kev vam meej txoj kev loj hlob. Lub mechanism ntawm lub matrix cia thiab kis tau tus mob ntawm kev tshuaj ntsuam genetic ntaub ntawv hloov mus rau hauv ib qhov system of caj coding, qhov twg lub ntsiab tivthaiv - ib tug haumxeeb chav tsev ntawm lub caj code.

Lub hauv paus dogma ntawm molecular biology uas

Caj - yog qhov tseem ceeb feem ntawm cov lom laaj ntawm lub neej. Xwm tau tsim mechanisms kis tau tus mob thiab tu tub tu kiv kev tshuaj ntsuam genetic ntaub ntawv los ntawm encoding cov proteins nyob rau hauv muaj pes tsawg leeg saw nucleic acids. Tso cai ntawm nucleic acids (DNA thiab RNA) - khaws cia cov ntaub ntawv thiab xa mus rau cov qauv ntawm cov proteins. Thiab cov nqaijrog los ntawm metabolic tshua nqa phenotypic qhia ntawm no cov ntaub ntawv. Cov kev tshuaj ntsuam genetic code - linear matrix khaws cia ntaub ntawv rau cov protein qauv los ntawm cov ntaubntawv povthawj siv nws triplets ntawm nucleotides nyob rau hauv lub nucleic acid saw. Tus me tshaj haumxeeb chav tsev ntawm caj code uas muaj cov lus qhia txog qhov tsawg kawg nkaus yam ntxwv tsev ntawm cov nqaijrog - ib tug triplet ntawm nucleotides nyob rau hauv lub DNA los yog RNA saw. ntaub ntawv raug kis los ntawm DNA rau mRNA thiab cov mRNA los ntawm lwm RNA thiab protein molecules.

Universal coding system

Nyob rau qhov kev nkag siab ntawm lub caj code nyob rau hauv science nws coj ib xyoo pua, thiab nws expansion - cia li ib xyoo caum. Txij li thaum cov kev taw qhia txog lub tswvyim ntawm cov qauv ntawm cov DNA ob helix (1953, Watson thiab Crick) tuaj mus rau to taub nws lub luag hauj lwm raws li lub roj ntsha cov khoom, thiab pib tshawb nrhiav rau cov tsiaj ntawv ntawm cov tsiaj ntawv, uas yog muab sau tseg rau nws cov ntaub ntawv. Lub tswv yim hais tias tus haumxeeb chav tsev ntawm lub caj code, ib tug nucleotide ib zaug yuav tsis sawv thuam. Plaub complementary nucleotide (adein, guanine, cytosine thiab thymine) DNA yuav encode cov nqaijrog 21 amino acids. Thom nug, physicists thiab biologists yog kev koom tes nyob rau hauv cov kev tshawb fawb rau ib tug encoding system thiab sai sai pom tias ib tug ib amino acid coding ib theem zuj zus ntawm peb nucleotides. Yog li, tej tsev kev tshuaj ntsuam genetic code - yog ib tug triplet ntawm nucleotides, lub luag hauj lwm rau lub synthesis ntawm ib tug protein amino acid. Peb (codons) ntawm 64, ntawm uas 61 - qhov kev txiav txim codons (encoding amino acid), thiab tshuav 3 - meaningless. Lawv tsis muaj ntaub ntawv hais txog cov amino acid, thiab ua raws li ib tug nres codon pib los yog ua kom tiav cov synthesis ntawm cov protein molecule.

Triplet - ib tug haumxeeb chav tsev ntawm caj code

Biopolymer nucleic acid molecule muaj monomers - nucleotides. Cov neeg, nyob rau hauv lem, tsim ib tug tas mus DNA uas ib tug transcription txheej txheem ntaub ntawv yog kis tau mus rau lub mRNA nyob rau hauv raws li cov kev nyeem ntawv ncej, qhov chaw uas qhov tsawg tshaj plaws code nqi muaj ib tug triplet ntawm nucleotides - t. nyeem ntawv ncej tsiv unidirectionally, thiab muaj ib tug meej kev tshuaj ntsuam genetic code thiab lub degeneracy ntawm unambiguity (redundancy).

Pointedness thiab uniqueness

Triplet ntaub ntawv yog unambiguous, i.e. lub ratio ntawm 1 t -1 amino acid yog tsis variably. Amino acid yuav kho thiab ob peb triplets, tab sis cov kev triplet - ib tug amino acid. nyeem ntawv ncej yog yeej ib txwm qhia nyob rau hauv tib txoj kev coj, thiab qhov no yog vim muaj cov triplets, pib nyeem thiab ua kom tiav nws. Qhov no ua rau cov stability ntawm cov protein qauv. Lwm cov khoom teejtug uas triplets - disjointness. Qhov no txhais tau tias lub nucleotide yog tas ib feem ntawm lub triplets, tab sis tsuas yog cia li ib tug.

Lub ntuj redundancy

Lub degeneracy ntawm lub (redundancy) ntawm lub caj code - qhov no yog ib tug muaj kev ruaj ntseg paj tau paj ntawm ib tug kab mob. Nws tiv thaiv hlwb tiv thaiv cov puas tsuaj ntawm change. Txhua haumxeeb chav tsev ntawm caj code undergo hloov 1, 2 thiab 3 nucleotides nyob rau hauv ib tug triplet. Yog li, 9 ntawm positional hloov nyob rau hauv txhua triplet nucleotide hloov nyob rau hauv txhua 4-1 = 3 tau embodiment, thiab raws li ib tug tshwm sim peb tau 61 los ntawm 9 = 549 variants hloov nucleotides nyob rau hauv ib tug triplet. Qhov no yog ntau npaum li cas tshaj yog tsim nyog los encode lub 21 amino acids. Qhov no pereizbytochnost los yog degeneracy, thiab muab cov roj ntsha hav zoov ntawm lub neej thiab txo mus rau ib tug tsawg kawg nkaus ntawm kom raug thaum nyeem cov kev tshuaj ntsuam genetic ntaub ntawv.

Codon los yog ib tug triplet?

Nyob rau hauv cov ntawv nyeem, ib tug triplet ntawm nucleotides, raws li ib tug ua hauj conglomerate hu ua ib tug triplet los yog codon. Yuav ua li cas yog qhov txawv thiab seb nws? Lub sij hawm "codon" yog siv nyob rau hauv qhov ncaj txheej txheem ntawm translation - hloov ntaub ntawv los ntawm RNA mus rau ib tug protein molecule. Lub sij hawm "triplet" yog siv nyob rau hauv ib tug dav heev semantic ntsiab lus teb, thaum piav txog cov ntaub ntawv kev nyeem ntawv ncej nrog ob RNA thiab DNA.