A degeneracy na kwayoyin code: kayan yau da kullum

A kayyade code da aka bayyana a matsayin codons, wani tsarin na shigar da bayanai game da tsarin sunadarai, muhimmi a duk rayayyun kwayoyin halitta na duniya. Mabudi dauki shekaru da dama, amma cewa ya wanzu, kimiyya da aka fahimta kusan karni. Versatility, bayani dalla-dalla, unidirectional, kuma musamman da degeneracy daga cikin kwayoyin code da akanta.

Tarihi na binciken

Matsalar shigar kwayoyin bayanai ya kasance kullum key a ilmin halitta. By da matrix tsarin da kwayoyin code, kimiyya cigaban wajen sannu a hankali. Tun da aka gano J. Watson da Crick a 1953. The biyu Helix tsarin DNA shiga wani lokaci na warware wani code tsarin da kanta, wanda ya sa da imani da girmanka yanayi. A mikakke tsarin sunadarai da DNA daga cikin wannan tsarin ya nuna gaban kwayoyin code, da rubutu tsakanin ayoyin biyu, amma rubuta tare da daban-daban alphabets. Kuma idan haruffa sunadaran da aka sani, da DNA alamomi sun batun nazarin ilmin halitta, kimiyyar lissafi da kuma lissafi.

Babu bukatar a bayyana duk matakai a cikin bayani na wannan daure. Direct gwaji, ya tabbatar da kuma tabbatar da cewa tsakanin DNA codons da kuma amino acid daga cikin sunadaran akwai wani fili da kuma m bi da bi aka gudanar a shekarar 1964 Charles Janowski kuma S. Brenner. A ci gaba da - a lokacin dikodi mai da kwayoyin code a vitro (a vitro) ta amfani da dabaru na gina jiki kira a cell-free Tsarin.

Cikakken decrypted code E. coli aka promulgated a shekarar 1966, masana kimiyyar, a taron, a Cold Spring Harbor (USA). Sa'an nan na buɗe da redundancy (degeneracy) na kwayoyin code. Abin da wannan na nufin, shi ya bayyana quite kawai.

dikodi mai ci gaba

Samun deciphering da hereditary code data ya zama daya daga cikin mafi muhimmanci abubuwan da suka faru na karshe karni. Yau, kimiyya ci gaba da gano a cikin zurfin cikin sunadaran kwayoyin tsarinsa tsarin da siffofin da wani overabundance, daga ãyõyin mu'ujizõji, abin da aka bayyana, a cikin dũkiyar degeneracy na kwayoyin code. A raba nazarin tattalin arziki - da asalin da kuma ci gaba na hereditary abu coding tsarin. Evidence haxe polynucleotides (DNA) da kuma polypeptides (proteins) ya ba impetus ga ci gaban ilmin sanin kwayoyin halittu. Kuma cewa, bi da bi, fasahar binciken halittu ta, bioengineering, binciken a cikin kiwo da kuma shuka girma.

Akidun da kuma dokoki

Home akidarsu na ilmin sanin kwayoyin halittu - da bayanin da aka canjawa wuri daga DNA to Manzo RNA, sa'an nan da ta kan gina jiki. A gaban shugabanci na watsa ne yiwu daga RNA zuwa DNA da RNA a kan sauran RNA.

Amma da matrix ko tushen DNA ko da yaushe ya kasance. Kuma duk sauran muhimman siffofin da bayanai canja wurin - a gani na da yanayin canja wuri na matrix. Wato, ta hanyar aikata watsa wa da kira na sauran matrix kwayoyin, wanda zai zama na haifuwa na tsarin kayyade bayani.

kwayoyin code

Layin coding tsarin sunadarai na gina jiki ta hanyar karin codons (triplets) nucleotides, wanda kawai 4 (adein, Bibyun, saitosin, taimain (uracil)), wanda spontaneously take kaiwa ga samuwar wasu sarƙoƙi na nucleotides. A wannan adadin nucleotides da kuma sinadaran complementarity - wannan shi ne babban sharadin irin wannan kira. Amma samuwar sunadaran kwayoyin ingancin matching da yawa da kuma ingancin da monomers ba (DNA nucleotides - gina jiki amino acid). Wannan shi ne da na halitta hereditary code - rikodi tsarin a cikin jerin nucleotides (codons) da amino acid jerin gina jiki.

Halitta code yana da dama Properties:

• Triplet.
• The musamman da suka bambanta.
• Wayarwa.
• Disjointness.
• Redundancy (degeneracy) na kwayoyin code.
• Versatility.

A nan ne taƙaitaccen bayanin, ya mayar da hankali a kan akanta.

Triplet, a ci gaba da kasancewa stoplights

Kowace daga 61 amino acid m zuwa na ginin jumla t (triplet) nucleotides. Uku triplets ba kawo bayanai game da amino acid kuma su ne tasha codons. Kowane nucleotide a cikin sarkar ne memba na triplet, kuma ba ya zama a kanta. A karshen da kuma farkon sarkar na nucleotides m zuwa guda gina jiki, suna tasha codons. Sun fara ko tasha watsa labarai (kira na sunadarin).

Bayani dalla-dalla, da kuma daya-pointedness disjointness

Kowane codon (triplet) encodes daya kawai amino acid. Kowane triplet ne m daga kuma ba zoba m. Daya nucleotide iya zama mallakin daya kawai triplet a cikin sarkar. Gina jiki kira ne ko da yaushe a daya shugabanci kawai, cewa ne sarrafawa tasha codons.

A redundancy da kwayoyin code

Kowane triplet na nucleotides encodes daya amino acid. A total na 64 nucleotides, 61 daga cikinsu - shigar wanda ke aiki amino acid (ma'ana codon), da kuma uku - ma'ana, watau amino acid ba encode (daina codons). A redundancy (degeneracy) na kwayoyin code shi ne cewa substitutions za a iya sanya a kowane triplet - m (abu don amino acid maye) da kuma ra'ayin mazan jiya (amino acid ba su canja aji). Abu ne mai sauki yin lissafi da cewa idan wani triplet za a iya aiwatar 9 substitutions (1, 2 da kuma 3 matsayi), kowane nucleotide za a iya maye gurbinsu da 4 - 1 = 3 da sauran embodiment, jimlar yawan yiwu nucleotide substitutions zai zama 61 ga 9 = 549.

A degeneracy na kwayoyin code da aka nuna a gaskiyar cewa 549 zabin - shi ne da yawa fiye zama dole ga zakodirovki bayanai game da 21 amino acid. A wannan yanayin na sauyawa zažužžukan 549 23 gubar da samuwar wani tasha codon, 134 + 230 canzawa - ne ra'ayin mazan jiya substitutions, da kuma 162 - m.

Sarauta degeneracy da aka ware

Idan biyu codons da biyu m farko nucleotide, sauran nucleotides an gabatar da wani aji (purine ko pyrimidine), da bayanai da suka kawo wannan amino acid. Wannan ne yawanci degeneracy ko redundancy da kwayoyin code. Biyu ware - AUA da UGA - na farko encodes methionine, ko da yake zai yi isoleucine, da kuma na biyu - wata tasha codon, amma zai yi encode tryptophan.

Ma'ana degeneracy da versatility

Wadannan biyu Properties daga cikin kwayoyin code sũ ne mafi girma nazarin halittu darajar. Duk da kaddarorin da aka jera a sama ne halayyar da kwayoyin bayanai na duk siffofin halittu a duniya tamu.

A degeneracy na kwayoyin code yana da wani Na'urar darajar, kamar yadda maimaita kwafi na amino acid code. Bugu da kari, wannan yana nufin wani gagarumin raguwa a (degeneration) na uku nucleotide a codon. Irin wannan embodiment minimizes da mutational raunuka a DNA, wadda ya kunsa tsanani take hakki a cikin furotin tsarin. Wannan shi ne m inji na rayayyun kwayoyin halitta na duniya.