DNA. Hauv DNA helix, lub hauv paus: adenine, cytosine, thymine thiab guanine yog txhua tus txuas nrog lawv cov hauv paus ntxiv los ntawm hydrogen bonding. Adenine ua ke nrog thymine nrog 2 hydrogen bonds. … Qhov sib txawv ntawm lub zog no yog vim qhov sib txawv ntawm tus lej ntawm hydrogen bonds.
Vim li cas cytosine thiab guanine muaj triple bonds?
Guanine thiab cytosine ua ib khub ntawm nitrogenous vim tias lawv muaj hydrogen daim ntawv cog lus pub dawb thiab hydrogen daim ntawv cog lus ua khub nrog ib leeg hauv qhov chaw. Guanine thiab cytosine tau hais kom ua tiav rau ib leeg.
Puas adenine tsim ob daim ntawv cog lus?
A purine (adenine lossis guanine) muaj ob lub nplhaib. Ib pyrimidine (cytosine los yog thymine) muaj ib lub nplhaib. Hauv DNA, purine yuav sib txuas nrog pyrimidine. Nyob ntawm tus qauv, nws yuav rau ob daim ntawv cog lus hydrogen nrog ib leeg lossis peb.
Dab tsi yog 2 qhov laj thawj vim li cas adenine khub nrog thymine thiab cytosine khub nrog guanine?
Nyob hauv DNA, adenine ib txwm ua khub nrog thyine thiab cytosine ib txwm ua khub nrog guanine. Cov khub no tshwm sim vim geometry ntawm lub hauv paus, s cia hydrogen bonds tsim tsuas yog ntawm "txoj cai" khub. Adenine thiab thymine yuav tsim ob daim ntawv cog lus hydrogen, thaum cytosine thiab guanine yuav tsim peb daim ntawv cog lus hydrogen.
Vim li cas adenine thiab thymine thiaj li muaj feem pua ?
Qhov no yog vim adenine yuavib txwm ua khub nrog thymine, yog li yuav muaj ntau npaum li thymine bases li adenine bases. Ua ke, adenine thiab thymine tsim 70% ntawm ntu. Qhov no txhais tau tias 30% ntawm ntu yog tsim los ntawm guanine-cytosine khub.
