{{Translated page}}
核酸(英語:nucleic acid)是一种通常位于细胞内的大型生物分子,主要負責生物体遗传信息的携带和传递。核酸有兩大類,分別是脱氧核糖核酸(DNA)和核糖核酸(RNA)。
核酸的单体结构为核苷酸。每一个核苷酸分子由三部分组成:一个五碳糖、一个含氮鹼基和一个或多个磷酸基团。如果其五碳糖是去氧核糖則為去氧核糖核苷酸,此單體之聚合物是DNA。如果其五碳糖是核糖則為核糖核苷酸,此單體之聚合物是RNA。
核酸是最重要的生物大分子(其余为胺基酸/蛋白质,醣類/碳水化合物和脂质/脂肪)。它们大量存在于所有生物,功能有编码、传递和表达遗传信息。换句话说,遺傳訊息通过核酸序列被传递。DNA分子含有生物物种的所有遗传信息,为双链分子,其中大多数是链状结构大分子,也有少部分呈环状结构,分子量一般都很大。RNA主要是负责DNA遗传信息的翻译和表达,为单链分子,分子量要比DNA小得多。
核酸存在于所有动植物细胞、微生物和病毒、噬菌体内,是生命的最基本物质之一,对生物的成长、遗传、变异等现象起着重要的决定作用。
核酸实验研究构成了现代生物学和医学研究的重要组成部分,形成了基因组和法医学,以及生物技术和制药行业的基础[7][8][9]。
核酸可以分为脱氧核糖核酸(DNA)、核糖核酸(RNA),以及人工合成的核酸类似物。
脱氧核糖核酸(DNA)是由脱氧核糖核苷酸构成的一种核酸。其主要负责生物体遗传信息的携带。组成DNA的碱基有四种:腺嘌呤(A)、鸟嘌呤(G)、胸腺嘧啶(T)与胞嘧啶(C)。DNA主要为双链构成的双螺旋结构,但病毒中也有单链DNA[4]。利用体外分子进化技术,也可合成出类似核酶的脱氧核酶[10]。
核糖核酸(RNA)由核糖核苷酸构成,其功能包括遗传信息的传递与核酶等,而一些病毒使用RNA携带遗传信息。组成RNA的碱基中,尿嘧啶(U)代替了胸腺嘧啶。RNA一般为单链。
除此之外,也可以通过人工合成出核酸类似物(英语:Nucleic_acid_analogue)(Nucleic acid analogues)。如肽核酸、锁核酸、GNA、苏糖核酸等。核酸类似物通过不同的分子骨架而与自然产生的DNA或RNA区分开来。
核酸由核苷酸组成,而核苷酸又是由含氮碱基、五碳糖和磷酸基构成。
核酸的单体结构为核苷酸。每一个核苷酸分子有三部分组成:一个含氮碱基,一个五碳糖和一个或多个磷酸基团。由含氮碱基和五碳糖组成的结构叫做核苷。
含氮碱基是两种母体分子嘌呤和嘧啶的衍生物。一般,组成核酸的碱基有五种,分别是:
除了以上五种碱基之外,部分核酸还含有特殊碱基。即稀有碱基。
核苷是由含氮碱基和戊糖组成的糖苷[5]。核苷加上一个磷酸基就是核苷酸。
核酸的结构可分为一级结构、二级结构、三级结构和四级结构。
核酸的链上各核苷酸残基的排列顺序被称作核酸的一级结构,即核酸序列。核酸序列在生物学中非常重要,它们不仅能区分核酸,还带有编码所有生物分子、分子装配体、亚细胞的和细胞的结构、器官的信息,和生物体的最终指令。
<ref>
ميّز عن المحفظة الجرثومية.تركيب غلام الخلية السالبة للغرام الغشاء الخارجي للبكتيريا يكون موجود في بكتيريا سلبية الغرام. الغشاء الخارجي يختلف عن الغشاء الخلوي- والجزء الخارجي من الغشاء يتضمن الدهون كثيرة السكريات عديد السكاريد الشحمي والدهون تمثل الذيفان الداخلي عد
NASCAR team Our MotorsportsOwner(s)Chris OurMary OurArlis “Vic” ReynoldsJack Perone FultonBaseWelcome, North Carolina[1]SeriesNASCAR Xfinity SeriesRace driversXfinity Series:02. David Starr, Kyle Weatherman, Blaine Perkins (R)SponsorsXfinity Series:02. Special Report, Larry’s Lemonade, Ollie's Bargain Outlet, PayDay, Warrior Health Foundation, To The Point Inc., Gratis Beer, Cape Cod Inflatable Park, AutoParkIt.com ManufacturerChevroletOpened2015CareerDebutNASCAR Xfinity Series:202…
A History of Modern Yoga SubjectModern yogaGenreSocial history, ReligionPublisherContinuumPublication date2004 A History of Modern Yoga is a 2004 book of social and religious history by the scholar of modern yoga Elizabeth De Michelis. It introduced a typology of modern yoga including modern postural yoga. Context Yoga became widespread in the Western world in the late 20th century, but received little academic attention until the 21st century, broadly starting with Elizabeth De Michelis's book,…
Former greyhound racing venue in London, England Not to be confused with Harringay Arena. Harringay StadiumLocationHarringay, LondonOperatorGreyhound Racing AssociationOpened1927Closed1987 Part of a series onHarringay History Overview Up to 1750 1750–1880 1880–present Locations Finsbury Park Railway Fields Warehouse District The Salisbury St Paul's Church Langham Men's Club Harringay station Harringay Gn La station Harringay Arena Harringay Stadium Harringay cinemas Other Harringay Online Pe…
Pour les articles homonymes, voir Dobro (homonymie). Guitare à résonateur de marque Dobro. Dobro est un nom de marque, propriété de Gibson Guitar Corporation, utilisé pour une certaine conception de guitare à résonateur. Le nom lui-même est intimement lié à l'histoire des instruments à résonateur : à l'origine créé par les frères Dopyera, nom fréquemment orthographié Dopera dans les sources américaines, le mot dobro vient de la contraction de Dopyera et de brothers. Dobro…
Índio do Brasil 18º Prefeito de Goiânia Período 7 de junho de 1976até 29 de junho de 1976 Antecessor(a) Daniel Antônio de Oliveira Sucessor(a) Goianésio Ferreira Lucas Dados pessoais Nascimento 11 de junho de 1936 (87 anos) Goiânia, Goiás Índio do Brasil Artiaga Lima (Goiânia, 11 de julho de 1936) é um político brasileiro. Filho dos políticos Getulino Artiaga - que dá nome ao plenário da Assembleia Legislativa do Estado de Goiás - e Berenice Teixeira Artiaga (primeira …
لمعانٍ أخرى، طالع جون كلارك (توضيح). هذه المقالة يتيمة إذ تصل إليها مقالات أخرى قليلة جدًا. فضلًا، ساعد بإضافة وصلة إليها في مقالات متعلقة بها. (يوليو 2019) جون كلارك معلومات شخصية الميلاد 20 فبراير 1952 (71 سنة) مواطنة المملكة المتحدة الحياة العملية المدرسة الأم كلية هي…
سيرخيو أغويرو Sergio Agüero أغويرو مع الأرجنتين في كأس العالم 2018 معلومات شخصية الاسم الكامل سيرخيو ليونيل أغويرو ديل كاستييو[1] الميلاد 2 يونيو 1988 (العمر 35 سنة)[2]كويلمس،[3] الأرجنتين الطول 1.73 م (5 قدم 8 بوصة)[4] مركز اللعب مهاجم الجنسية الأرجنتين الزوجة جيان…
Strategic government policy Green Industrial PolicyGreen industrial policy seeks to address market failures and protect the environment. Green industrial policy (GIP) is strategic government policy that attempts to accelerate the development and growth of green industries to transition towards a low-carbon economy.[1][2] Green industrial policy is necessary because green industries such as renewable energy and low-carbon public transportation infrastructure face high costs and ma…
هذه المقالة يتيمة إذ تصل إليها مقالات أخرى قليلة جدًا. فضلًا، ساعد بإضافة وصلة إليها في مقالات متعلقة بها. (أغسطس 2021) مراقب الجفاف بالولايات المتحدة عبارة عن مجموعة من الإجراءات التي تسمح للخبراء بتقييم حالات الجفاف في الولايات المتحدة. جهاز الرصد ليس وكالة بل هو شراكة بين ال…
Christa Wolf (1963) Christa Wolf fotografiert von Oliver Mark in ihrer Wohnung in Berlin-Pankow, 2010 Christa Wolf (geb. Ihlenfeld; * 18. März 1929 in Landsberg an der Warthe; † 1. Dezember 2011 in Berlin) war eine deutsche Schriftstellerin. Sie zählte zu den bedeutendsten Schriftstellerpersönlichkeiten der DDR und wurde vielfach ausgezeichnet, u. a. mit dem Georg-Büchner-Preis. Ihr Werk wurde in viele Sprachen übersetzt. Inhaltsverzeichnis 1 Leben 1.1 Jugend, Ausbildung und Familie …
Giải bóng đá vô địch thế giới 1958Världsmästerskapet i FotbollSverige 1958Poster chính thứcChi tiết giải đấuNước chủ nhà Thụy ĐiểnThời gian8 – 29 tháng 6Số đội16 (từ 3 liên đoàn)Địa điểm thi đấu12 (tại 12 thành phố chủ nhà)Vị trí chung cuộcVô địch Brasil (lần thứ 1)Á quân Thụy ĐiểnHạng ba PhápHạng tư Tây ĐứcThống kê giải đấuSố…
The former Carlos'n Charlie's in Oranjestad, Aruba A seafood dish at Mul Yam restaurant, located at Tel Aviv Port, Tel Aviv, Israel Stuffed blue crab shells known as Casquinha de Siri being enjoyed in Tropicana Restaurant at Rio de Janeiro City A bobó de camarão dish at a Rio de Janeiro restaurant The following is a list of notable seafood restaurants. A seafood restaurant typically specializes in seafood cuisine and seafood dishes, such as fish and shellfish. Seafood restaurants This is a dyn…
Organization Professional Bowlers AssociationAbbreviationPBAFormation1958PurposeProfessional association for ten-pin bowling; governing body is USBCHeadquartersChicago, Illinois[1]Region served WorldwideMembership 3,000+ representing 30 countries[2]PBA CommissionerTom Clark[3]Parent organizationBowlero Corporation[2]Staff 19[4]Websitewww.pba.com The Professional Bowlers Association (PBA) is the major sanctioning body for the sport of professional ten-pin b…
Dieser Artikel handelt von einem Bauwerk in Königstein im Taunus. Zum gleichnamigen Bauwerk in Pforzheim siehe Villa Rothschild (Pforzheim). Villa Rothschild Hotelkette Autograph Collection by Marriott Stadt Königstein im Taunus Adresse Im Rothschildpark 1 Website brhhh.com/villa-rothschild Hotelinformationen Eröffnung 1956 Besitzer Broermann Health & Heritage Hotels GmbH[1] Leitung Ivo Schramm, Dirk Schäfer[1] Klassifizierung 5 Sterne Superior Ausstattung Zimmer 22 Resta…
Postcard artwork of the Star and Garter Hotel in the 1890s The Star and Garter Hotel in Richmond was a hotel located in the London countryside (later suburbs) on Richmond Hill overlooking the Thames Valley, on the site later occupied by the Royal Star and Garter Home, Richmond. The first establishment on the site, an inn built in 1738, was relatively small. This was followed by several other buildings of increasing size and varied design as the site changed from family ownership to being run by …
Norwegian chieftain Kálfr Árnason with the young Magnus at Stiklestad; illustration by Halfdan Egedius for the Saga of Magnus the Good in Heimskringla Kálfr Árnason (modern Norwegian Kalv Arnesson; c. 990 – 1051) was an 11th-century Norwegian chieftain who played a major role both in defeating King Olaf Haraldsson (later named St. Olaf) at the Battle of Stiklestad and in bringing back his young son Magnus and raising him to the throne. Kálfr was a son of Árni Arnmódsson or Arm…
Some of this article's listed sources may not be reliable. Please help this article by looking for better, more reliable sources. Unreliable citations may be challenged or deleted. (March 2023) (Learn how and when to remove this template message) Rap RebirthType of siteLyric writing serviceAvailable inEnglishOwnerPrivately ownedURLhttp://www.rap-rebirth.comCommercialYesRegistrationNoneLaunched2008Current statusActive Rap Rebirth is an online hip-hop ghostwriting service. It was founded…
Đừng nhầm lẫn với Đô đốc Hạm đội Liên Xô. Bài này viết về cấp bậc tương đương đô đốc 4 sao của Liên Xô. Đối với cấp bậc cao cấp trong lực lượng hải quân Anglophone, xem Thủy sư đô đốc. Đối với các định nghĩa khác, xem Đô đốc hạm đội (Nga). Đô đốc hạm đội(Адмирал флота)Cấp hiệu cầu vai (1955–1990)Sao nguyên soái (loại nhỏ)Quốc gia Liên XôThuộc Hải quâ…
1948 film by John Farrow The Big ClockTheatrical release posterDirected byJohn FarrowScreenplay byJonathan LatimerBased onThe Big Clockby Kenneth FearingProduced byRichard MaibaumStarringRay MillandCharles LaughtonCinematographyJohn F. SeitzDaniel L. Fapp (uncredited)Edited byLeRoy StoneEda Warren (supervisor)Music byVictor YoungColor processBlack and whiteProductioncompanyParamount PicturesDistributed byParamount PicturesRelease date April 9, 1948 (1948-04-09) (United States)…
Lokasi Pengunjung: 3.142.156.235