2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
tRNA, nrhiav tau los ntawm Paul Zamecnik thiab cov neeg koom tes [2], yog ib qho "adaptor" molecule [3] uas kho cov kev txhais cov ntaub ntawv los ntawm tus xa xov RNAs (mRNAs). tRNA yog thawj qhov tsis-coding RNA tau pom.
Thaum twg tRNA nrhiav tau?
Nws tau ua haujlwm hauv bacteriology thiab immunology department ntawm Harvard Medical School los ntawm 1952 txog 1967. Ua hauj lwm ua ke nrog Paul Zamecnik thiab Elizabeth Keller nws nrhiav tau thawj kauj ruam ntawm protein synthesis. Ob xyoos tom qab ntawd hauv 1958 Hoagland thiab Zemecnik pom tRNA.
Tus qauv ntawm tRNA hu ua dab tsi?
Lub tRNA molecule muaj qhov sib txawv folded qauv nrog peb plaub hau loops uas tsim cov duab ntawm peb nplooj clover. Ib qho ntawm cov kab plaub hau no muaj cov kab ke hu ua anticodon, uas tuaj yeem paub thiab txiav txim siab ib qho mRNA codon. Txhua tRNA muaj nws cov amino acid uas txuas mus rau nws qhov kawg.
tRNA nyob qhov twg?
tRNA lossis Hloov RNA
Zoo li rRNA, tRNA nyob nyob rau hauv lub cellular cytoplasmthiab koom nrog hauv cov protein synthesis. Hloov RNA coj lossis hloov cov amino acids mus rau ribosome uas sib haum rau txhua peb-nucleotide codon ntawm rRNA.
Lub hauv paus chiv keeb ntawm tRNA yog dab tsi?
Ib tus qauv rau tRNA molecule keeb kwm yog tham. Tus qauv postulates tias cov molecule no originated tsuas yog los ntawm kev duplication ncaj qha (thiab tom qab evolution) ntawm cov noob coding rau RNA hairpin qauv, uas tuaj yeemyog li no yuav tsum hypothesized raws li evolutionary precursor ntawm tRNA molecule.
Pom zoo:
Leej twg tau npaj ob chav helical qauv ntawm dna?
In 1953, Francis Crick thiab James Watson thawj zaug piav txog cov qauv molecular ntawm DNA, uas lawv hu ua "ob chav helix," hauv phau ntawv journal Nature. Rau qhov kev tshawb pom no, Watson, Crick, thiab lawv cov npoj yaig Maurice Wilkins Maurice Wilkins Nws tau paub zoo tshaj plaws rau nws txoj haujlwm ntawm King's College London ntawm tus qauv ntawm DNA.
Leej twg nrhiav tau induced haum txoj kev xav?
Tus qauv tsim kom haum yog thawj zaug los ntawm Koshland hauv xyoo 1958 los piav qhia txog kev hloov pauv ntawm cov protein hauv cov txheej txheem khi. Cov qauv no qhia tau hais tias ib qho enzyme, thaum khi nrog nws cov substrate, optimizes lub interface los ntawm lub cev kev sib cuam tshuam los tsim ib tug complex qauv.
Leej twg nrhiav tau sulfuric acid?
Qhov kev tshawb pom ntawm sulfuric acid tau lees paub rau 8th caug xyoo alchemist Jabir ibn Hayyan. Sulfuric acid ua ntej li cas? Nyob rau xyoo pua 17th, German-Dutch chemist Johann Glauber tau npaj sulfuric acid los ntawm kev hlawv sulfur ua ke nrog ntsev (potassium nitrate, KNO 3 ), nyob rau hauv lub xub ntiag ntawm chav.
Leej twg tau spayed thiab leej twg tau txais neutered?
Kev npam tus dev hais txog kev tshem tus poj niam dev lub cev xeeb tub, hos neutering yog hais txog cov txheej txheem uas ua rau txiv neej. Thaum tus poj niam tus dev tau spayed, tus kws kho tsiaj tshem nws zes qe menyuam thiab feem ntau nws lub tsev menyuam thiab.
Puas nrhiav tau lossis nrhiav tau?
Yog li, koj yuav tsum tau siv "could find". Lub modal verb, tau yog twb nyob rau hauv nws paste-form: ua. Yog li koj tsis tas yuav hloov pauv los nrhiav. Yuav nrhiav tau lossis nrhiav tau? "Ntaus" yog sib npaug. "
