Namhlanje siza kuthetha iziseko ze nitrogen. Zizo ezo eziqulethe ulwazi lwemfuza kwaye zenziwe ngee-purines ezimbini kunye nee-pyrimidines ezimbini. IiPurines zaziwa njengeAdenine kunye neGuanine, ngelixa iPyrimidines yaziwa ngokuba yiThymine kunye neCytosine. ITroj kwii-fairies ibaluleke kakhulu kwi-DNA yomntu.
Ke ngoko, siza kulinikela eli nqaku ukuba likuxelele yonke into ekufuneka uyazi malunga neziseko ze-nitrogen, iimpawu kunye nokubaluleka kwazo.
Iimpawu zenyukliya
Xa sithetha ngee-nucleic acid sibhekisa kwii-biomolecule ezo zinolwazi lwemfuzo. Ziyi-biopolymers ezinobunzima obuphezulu beemolekyuli kwaye zenziwa ngamanye amacandelo amancinci alungeleleneyo abizwa ngokuba zii-nucleotides. Ukuba siyayihlalutya ngokwembono yeklinikhi, ii-acid ze-nucleic ziimolekyuli ezinkulu ezenziwe ngee-polymers zomgama zee-nucleotide. Zonke iipolymers ezidityaniswe yimixokelelwane ye-phosphate ester ngaphandle kwexesha.
Kule meko, ii-acid ze-nucleic zahlulwe zaba yi-deoxyribonucleic acid efumaneka ihlala kwinucleus yeeseli kunye nezinye i-organelles kunye ne-ribonucleic acid efumaneka kwisytoplasm. Zenziwe ngamatyathanga amade ee-nucleotide ezidityaniswa ngamaqela e-phosphate. Akukho hlobo lwamaxesha lufunyenwe phakathi kwezi khonkco. Ezona molekyuli zinkulu zenziwe ngamakhulu ezigidi zeenukotoyidi kwisakhiwo esinye esidibeneyo. Oku kungenxa yokuba iqondo lokumodareyitha phakathi kwee-nucleotide linokuphakama kakhulu.
Ngendlela efanayo, iiproteni esizityayo ekutyeni nazo ziipolima ezilungelelaniswe ngamaxesha athile ziiamino acid. Oku kunqongophala kwamaxesha kubangela ubukho bolwazi. Izazinzulu ziyifumene loo nto iicicic acid yindawo yokugcina ulwazi yazo zonke ii-amino acid ezilandelelanayo zazo zonke iiproteni zeseli. Kuyaziwa ukuba kukho unxibelelwano phakathi kokulandelelana kokubini, okuchazwa ngokuthi ii-nucleic acid kunye neeproteni zenziwe nge-collinear. Inkcazo yako konke oku kulungelelaniswa yaziwa njengekhowudi yemfuza. Ikhowudi yemfuza yiyo emisela ukulandelelana kwee-nucleotide ngaphakathi kwe-acid ye-nucleic ehambelana ne-amino acid kwiproteni.
Kufuneka kukhunjulwe ukuba ziimolekyuli ezinolwazi lofuzo lwezinto eziphilayo kwaye zinoxanduva lokudlulisela kwilifa.
Iziseko zeNitrogen
Ulwazi malunga nokwakheka kwee-nucleic acid lusivumele ukuba sifunde ngakumbi malunga nekhowudi yemvelo yomntu. Ndiyabulela koku, siyayazi indlela kunye nolawulo lweprotein synthesis kunye indlela yokuhanjiswa kolwazi lwemfuzo ukusuka kwiiseli zeziqu ukuya kwiiseli zentombi.
Yilapho ukubaluleka kweziseko ze-nitrogen ziqala ukungena. Zimbini iintlobo zeecicic acid, njengoko besesitshilo apha ngasentla. Bahluke nje phakathi kwabo ngeswekile abayiphetheyo. Kwelinye icala sine-deoxyribose kwaye kwelinye icala ribose. Zikwahlula-hlulwe ziziseko ze-nitrogen. Kwimeko ye-DNA, sinayo adenine, guanine, cytosine, kunye ne-thymine. Kwelinye icala, kwi-RNA sine adenine, guanine, cytosine, kunye ne-uracil. Umahluko kukuba ubume beetyathanga zeziseko ze-nitrogen zihlukile kwi-DNA nakwi-RNA. Ngelixa likwi-DNA zingumtya ophindwe kabini, kwi-RNA ngumtya omnye.
Inkcazo kunye neentlobo zeziseko ze-nitrogen
Siyazi ukuba iziseko ze-nitrogen yilezo ziqulethe ulwazi lofuzo. Ngelixa iziseko zepurimidine kunye nepyrimidine zinencasa kwaye zithe tyaba. Oku kubalulekile xa sijonga ukwakheka kwee-acid ze-nucleic. Kuya kufuneka ndikhumbule ukuba iziseko ze-nitrogen ezingenakunyibilika emanzini kwaye zinokuseka unxibelelwano oluthile lwe-hydrophobic phakathi kwazo. Oko kukuthi, azinakunxulumana kunye.
Ezi mpawu zenziwe ziziseko ze-nitrogen ukuzinzisa ulwakhiwo olunemilinganiselo emithathu yeecicic acid ezenza iDNA. Iziseko zeNitrogen zihlala zifunxa ukukhanya kwaye xa zikuluhlu lwe-ultraviolet spectrum ye-electromagnetic phakathi kwamaxabiso e-250-280nm. Le propati isetyenzisiwe okoko yafunyanwa zizazinzulu ngokufunda kwayo kunye nokulinganisa.
Iziseko zepuric zisekwe kwindandatho yePurine. Ziyabonakala kuba ziyinkqubo yekayiti enee-atom ezisi-9, ezi-5 zazo ziikhabhon kwaye ezi-4 zazo zii-nitrogens. Inkqubo ye- I-Adenine kunye neGuinea zenziwe nge-purine. Iipyrimidine nitrogenous bases zisekwe kwindandatho ye-pyrimidine. Yinkqubo ethe tyaba eneeathom ezi-6, ezi-4 zazo ziikhabhon kunye nezinye ezi-2 zii-nitrogens.
Iziseko eziguqulweyo kunye nee-nucleosides
Iziseko ze-pyrimidine zonakaliswe ngokupheleleyo emanzini, icarbon dioxide kunye ne-urea. Ukongeza kwi-purine kunye ne-pyrimidine esisekhe saxoxa ngayo, sinokufumana iziseko eziguqulweyo Ezona ziseko ziguquliweyo zininzi zi-5-methylcytosine, 5-hydroxymethylcytosine, kunye ne-6-methyladenine, edityaniswe kummiselo wentetho ye-DNA. Kwelinye icala, nathi sinayo I-7-methylguanine kunye ne-dihydrouracil eyinxalenye yesakhiwo se-RNA, kuba ine-uracil.
Ezinye iziseko ezilungiswa rhoqo ziHypoxanthine kunye neXanthine. Bangama-metabolic intermediates aziimveliso zempendulo ye-DNA ngezinto ezinomzimba.
Njengee-nucleosides, yimanyano yesiseko sepentose esenzeka ngokudibana kwe-glycosidic phakathi kwekhabhoni yenye yethambo okanye i-deoxyribose kunye ne-nitrogen yesiseko se-nitrogen. Kwimeko ye-pyrimidines zibopha nge-nitrogen 1, ngelixa kwi-purines zibopha nge-nitrogen 9. Kufuneka kuthathelwe ingqalelo ukuba kule manyano imolekyuli yamanzi ilahlekile.
Oososayensi bazama ukunqanda ukudideka kwigama lokuchazwa kwee-nucleosides kunye ne-nucleosides kwaye ke, amanani alandelwa sisimelabizo xa kuthethwa ngee-pentose atom. Ngale ndlela, inokwahlulahlulwa kwesiseko se-nitrogen.
Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga neziseko ze-nitrogen kunye neempawu zazo.