Yuav ua li cas plaub nitrogen bases ua ke?
Yuav ua li cas plaub nitrogen bases ua ke?

Video: Yuav ua li cas plaub nitrogen bases ua ke?

Video: Yuav ua li cas plaub nitrogen bases ua ke?
Video: dr nyiaj looj yaj lus qhuab qhia yuav ua li cas peb thiaj nyob laus tau ua ke 2024, Kaum ib hlis
Anonim

Pair ua ke tshwm sim thaum nitrogenous bases ua hydrogen bonds nrog ib leeg. Txhua puag muaj ib tus khub tshwj xeeb: guanine nrog cytosine, adenine nrog thymine (hauv DNA) lossis adenine nrog uracil (hauv RNA). Cov hydrogen bonds tsis muaj zog, tso cai rau DNA kom 'unzip'.

Xav txog qhov no, yuav ua li cas nitrogen bases ib txwm ua khub?

Cov nitrogenous bases tsim hydrogen bonds ntawm opposing DNA strands rau tsim cov rungs ntawm "twisted ladder" los yog ob chav helix ntawm DNA los yog ib tug lom catalyst uas muaj nyob rau hauv cov nucleotides. Adenine yog ib txwm ua ke nrog thymine, thiab guanine yog ib txwm ua ke nrog cytosine. Cov no yog lub npe hu ua puag khub.

Tsis tas li ntawd, plaub lub hauv paus nitrogen hauv DNA yog dab tsi thiab lawv qhov tseem ceeb yog dab tsi? A nitrogenous puag tsuas yog ib nitrogen -muaj cov molecule uas muaj cov tshuaj lom neeg zoo ib yam li a puag . Lawv tshwj xeeb tseem ceeb txij li thaum lawv ua lub tsev blocks ntawm DNA thiab RNA: adenine, guanine, cytosine, thymine thiab uracil.

Tsis tas li ntawd, dab tsi yog qhov tseem ceeb ntawm qhov sib lawv liag ntawm lub hauv paus khub?

Lawv sawv cev rau adenine, thymine, cytosine, thiab guanine. Plaub qhov sib txawv bases khub ua ke nyob rau hauv ib txoj kev hu ua complementary ua khub . Adenine ib txwm khub nrog thymine, thiab cytosine ib txwm khub nrog guanine. Cov ua khub Qhov xwm ntawm DNA muaj txiaj ntsig zoo vim nws tso cai rau kev rov ua dua tshiab yooj yim dua.

Vim li cas AC thiab GT tsis tuaj yeem ua khub?

Cov kev npaj ntawm atoms nyob rau hauv plaub yam ntawm nitrogenous bases yog xws li hais tias ob hydrogen bonds yog tsim tau txais thaum A thiab T nyob rau opposite DNA strands, thiab peb yog tsim thaum G thiab C los ua ke li no. A-C los yog G-T sib yuav tsis tau daim ntawv zoo sib xws ntawm cov hydrogen bonds.

Pom zoo: