⚡ Jelaskan Struktur Dna Dengan Bagan Menurut Watson Dan Crick

A fosfat dan basa N. B. deoksiribosa dan basa N. C. fosfat dan deoksiribosa. D. ribosa dan fosfat. E. ribosa dan basa N. Pembahasan: Watson dan Crick menyatakan bahwa struktur DNA berupa double helix tersusun dari anak tangga dan ibu tangga. Ibu tangga terdiri dari fosfat dan deoksiribosa. Jawaban: C-----#----- Websitetentang pelajaran Biologi, praktikum Biologi, dan media informasi pendidikan. Website tentang pelajaran Biologi, praktikum Biologi, dan media informasi pendidikan Watson dan Crick sang penemu struktur DNA (1) dna_structure; dna_structure. Facebook Comments Box. Related Posts. Idik Sulaeman : Pencipta logo OSIS dan PASKIBRAKA Jelaskan Jawab: Struktur DNA menurut Watson dan Crick (1953) berupa tangga tali terpilin ganda (double helix) yang tersusun dari berikut. Gula dan fosfat sebagai induk/ibu tangga. Basa-basa nitrogen dengan pasangan tetapnya sebagai anak tangga. Basa nitrogen dari kedua rantai polinukleotida berpasangan sesuai aturan Chargaff, yaitu A dengan T jelaskanstruktur dna dengan bagan menurut watson dan crick - Agustus 2022 KULIAHKECHINA.COM. Info terkini jelaskan struktur dna dengan bagan menurut watson dan crick. Apakah Anda sedang mencari informasi terbaru di KULIAHKECHINA.COM tentang jelaskan struktur dna dengan bagan menurut watson dan crick ini? Jika Anda tidak menemukan info mengenai jelaskan struktur dna dengan bagan menurut watson ModelDNA menurut Watson dan Crick berupa tangga tali berpilin ganda (double helix) yang tersusun sebagai berikut. Gula dan fosfat sebagai induk/ibu tangga. Basa-basa nitrogen dengan pasangan tetapnya sebagai anak tangga. Share : Post a Comment for "Jelaskan model DNA menurut Watson dan Crick!" Newer Posts Older Posts Pondok Budaya Bumi Olehkarena itu, gula tersebut dinamakan de-oksi yang berarti kehilangan oksigen. Pada rantai punggung DNA (DNA backbone), gula deoksiribosa kemudian terhubung dengan suatu gugus fosfat, tepatnya pada atom karbon nomor 5 dari gula deoksiribosa. Jadi menurut Crick dan Watson DNA memiliki struktur double helix (ganda berpilin). Pengertiandan Struktur DNA. Pengertian dan Struktur DNA - Pada tahun 1953, James Watson, Francis Crick, Maurice Wilkins dan Rosalind Franklin menemukan struktur DNA. Asam deoksiribonukleat atau DNA adalah biomolekul yang berisi instruksi genetik pada organisme, untuk hidup dan berkembang biak. Instruksi ini ditemukan dalam setiap sel, dan StrukturDNA beserta bagan menurut Watson dan Crick adalah . Jawaban Pendahuluan. DNA merupakan penyusun gen pada kromosom di dalam nukleus atau inti sel. Namun, DNA juga ditemukan pada mitokondria, sentriol, kloroplas, dan plastida. Pada organisme tertentu DNA terdapat dalam sitoplasmanya seperti katak, Amoeba, Paramaecium, dan tumbuhan paku. SebelumCrick dan Watson menemukan struktur DNA, Maurice Wilkin menunjukkan hasil fotografi X-ray milik Franklin. Crick, Watson, dan Wilkins mendapat Nobel Kedokteran atas penemuan ini. Sayangnya, Franklin meninggal tahun 1958 sehingga tidak memenuhi persyaratan untuk mendspatkan penghargaan itu.[ 4 ] M72aU. Bagaimana struktur kimia DNA menurut Watson & crickjelaskan struktur double helix DNA berdasarkan watson-crickjelaskan struktur double helix dna menurut watson-crick!jelaskan struktur double helix dna menurut struktur dna dgn bagan berdasarkan watson & crick! Struktur DNA beserta denah berdasarkan Watson & Crick yakni ….JawabanPendahuluanPembahasanKesimpulanPelajari lebih lanjut Detil Jawaban Jawaban DNA merupakan penyusunan gen pada kromosom di dlm nukleus atau inti sel tetapi DNA pula ditemukan pada mitokondria sentrio kloroplas & plastisida. pada organisme tertentu & dapat dlm sitoplasmanya mirip katak amoeba paramecium & flora paku DNAdeoxyribonucleic acid adalah substansi pembawa informasi genetik dr suatu generasi ke generasi mempunyai sifat antara lain berupa makromolekul asam nukleat bersifat awet sebab mampu bereplikasi menggandasehingga mampu diperbanyak & diwariskan pada keturunannya, dapat menjadi cetak isyarat-kode genetik untuk selanjutnya diterjemahkan menjadi asam asam amino penyebut protein & mempunyai teladan pola urutan nukleotida yg berlawanan-beda pada setiap orang kecuali kembar identik DNA mampu bersifat heterokatalitik & autokatalitik. DNA bersifat HETEROKATALITIK alasannya adalah mampu menciptakan RNA lewat sistensi protein & bersifat AUTOKATALITIKkarena mampu melakukan replikasi menciptakan DNA gres. replikasi yakni proses penggandaan DNA untuk memperbanyak diri yg terjadi pada fase sintesis saat interfase menjelang Sel akan membelah. tujuan semoga sel anak hasil pembelahan mengandung DNA yg identik dgn DNA sel induknya. kesalahan dlm replikasi DNA dapat menjadikan pergeseran pada sifat sel anak nya terdapat tiga model makanisme replikasi DNA yaitu 1 MODEL KONSERVATIF ketua untai polinukleotida induk atau yg lama tak berganti & fungsi sebagai cetakan. Makara heliks ganda DNA gres tak mengandung polinukleotida lama. 2 versi semikonservatit kedua untai polinukleotida berpisah tetapi masing-masing membentuk untai polinukleotida baru selaku pelengkap. tadi diperoleh dua heliks ganda & e masing-masing mengandung molekul DNA usang & gres dengan-cara berselang seling kata ketua untai polinukleotida 3 MODEL DISPERSIF beberapa cuilan kedua untai polinukleotida usang dengan-cara tersebar berfungsi sebagai cetakan kemudian masing-masing cuilan menciptakan cuilan-serpihan polinukleotida baru selaku pelengkapnya. tadi diperolehkan 2 He likes a & b yg masing-masing mengandung molekul DNA usang & DNA baru dengan-cara berselang seling pada kedua untai polinukleotida PEMBAHASAN model struktur molekul DNA ditemukan oleh James Watson & Francis crick Pada tahun 1953. DNA mempunyai struktur heliks ganda double Helix berpilin & ilustrasikan selaku tangan tali terpilih ke arah kanan struktur DNA yg double Helix adalah sebuah polimer yg terdiri dr nukleotida nukleotida. nukleotida yg tak memiliki gugus fosfat disebut nukleosida atau dioksirinukleosida. Nukleosida merupakan prekursor dlm sintesis DNA. Setiap nukleotida terdiri atas tiga komponen yaitu 1 gula pentosa deoksiribosa ribosa yg kehilangan satu atom oksigen nya 2 gugus fosfat 2 basa nitrogen yg terdiri dr dua jenis sebagai berikut Purin ada dua macam yaitu guanin G & ADENIN A Pirimidin ada dua macam yakni timin Tdan sitosin S/C struktur heliks ada & dapat diilustrasikan sebagai tangga tali berpilin. fosfat dr sebuah nukleotida akan membentuk ikatan fosfodiester dgn gula dr nukleotida berikutnya. Ikan gula dgn fosfat diilustrasikan sebagai tulang belakang gula fosfat atau ibu rumah tangga. sementara itu basa nitrogen purin pada suatu nukleotida akan membentuk ikatan hidrogen sebagai pasangan tetap dgn pirimidin dr nukleotida lainnya. Ikatan bahasa purin pirimidin diilustrasikan sebagai anak tangga. Ikatan hidrogen yg dibuat adenin dgn timin adalah 2 ikatan hidrogen A=T, sedangkan guanin dgn si tosin membentuk tiga ikatan hidrogenG=G Kesimpulan Menurut Watson & crick adalah heliks ganda double heliks jelaskan struktur double helix DNA berdasarkan watson-crick 1. Sifat anti paralel yg dimiliki kedua molekul ini, hal ini bisa dilihat dr Ikatan kovalen yg terjadi akhir salah satu ujung tak mempunyai ikatan Pasangan Adenin-Timin dihubungkan pada 3 Molekul DNA mempunyai dua untaian polinukleotida yg Basa nitrogennya mempunyai korelasi dgn basa nitrogen yg yang Rantai khususnya terdiri dr gugus gula pentosa & pula gugus fosfat. jelaskan struktur double helix dna menurut watson-crick! Kelas XII Mata pelajaran Biologi Materi Genetika Kata kunci struktur molekul DNA Saya akan menjawab pertanyaan ini dgn dua jawaban JawabanPendek Struktur double helix Helix ganda adalah gambaran strukturmolekul DNA, yg tersusun dr dua untaian pita dr heliks ganda, yg tersusundari rangkaian nukleotida. Nuklotida yang dibuat dr gugus gula & gugus fostat. Kedua untaian pita heliks ini dihubungkan lewat ikatan basanitrogen antara dau pasangan nukleotida yg berhadapan, oleh empat jenis basanitrogen adenin A, sitosin C, guanin G, atau timin T. Jawaban Panjang Heliks ganda yakni deskripsi bentuk molekuler dr molekul DNA asamdioksiribo nukleat yg beruntai ganda. Pada tahun 1953, Francis Crick danJames Watson pertama-tama menggambarkan struktur molekul DNA, yg mereka sebut“heliks ganda”, di jurnal Nature. Untuk inovasi terobosan ini, Watson, Crick, & rekanmereka Maurice Wilkins mengungguli Hadiah Nobel dlm bidang Fisiologi, atauKedokteran, pada tahun 1962. Molekul DNAterdiri dr dua untaian pita yg saling berhadapan & berputar, miriptangga yg melengkung atau bengkok. Untaian ini tersusun atas molekul linearpanjang, yg dibikin dr unit yg lebih kecil yg disebut nukleotida. Nukleotida inisaling mengikat hingga membentuk rantai atau pita yg panjang. Setiap nukleotidadi untaian pita yang dibuat dr gugus gula deoksiribosa & gugus fosfat yangberselang-seling. Pada masing-masingnukleotida di pecahan gugus gula Ribosa, terikat satu dr empat jenis basanitrogen adenin A, sitosin C, guanin G, atau timin T. Basa nitrogenini akan mengikatkan nukleotida dgn nukleotida pasangannya. Dalam ikatanbasa nitrogen ini, adenin akan membentuk pasangan basa dgn timin A-T, dansitosin membentuk pasangan basa dgn guanin C-G. jelaskan struktur double helix dna menurut watson-crick James Watson & Francis Crick mengemukakan model struktur molekul 3 dimensi DNA yg berbentuk untai panjang heliks ganda yg berpilin ke arah kanan. Menurut mereka, setiap nukleotid terdiri dr gula pentosa deoksiribosa,gugus fosfat,4 jenis basa nitrogen. Fostat akan berikatan dgn gula pentosa dgn membentuk ikatan fosfodiester sbg “Tulang Belakang” & pasangan basa nitrogen sbg anak tangganya struktur dna dgn bagan berdasarkan watson & crick! Struktur DNA beserta denah berdasarkan Watson & Crick yakni …. Jawaban Pendahuluan DNA merupakan penyusun gen pada kromosom di dlm nukleus atau inti sel. Namun, DNA pula ditemukan pada mitokondria, sentriol, kloroplas, & plastida. Pada organisme tertentu DNA terdapat dlm sitoplasmanya seperti katak, Amoeba, Paramaecium, & flora paku. DNA deoxyribonucleic acid yaitu substansi pembawa gosip genetik dr sebuah generasi ke generasi berikutnya. DNA mempunyai sifat antara lain berupa makromolekul asam nukleat, bersifat abadi alasannya adalah dapat bereplikasi mengganda sehingga mampu diperbanyak & diwariskan pada keturunannya, mampu menjadi cetak kode-aba-aba genetik untuk selanjutnya diterjemahkan menjadi asam-asam amino penyusun protein, & mempunyai acuan-pola urutan nukleotida yg berlawanan-beda pada setiap orang kecuali kembar identik. DNA mampu bersifat heterokatalitik & autokatalitik. DNA bersifat heterokatalitik alasannya mampu membentuk RNA melalui sintesis protein, & bersifat autokatalitik karena mampu melakukan replikasi menghasilkan DNA gres. Replikasi ialah proses penggandaan DNA utuk memperbayak diri yg terjadi pada fase sintesis saat interfase mejelang sel akan membelah. Tujuannya semoga sel anakan hasil pembelhan mengandung DNA yg identik dgn DNA sel induknya. Kesalahan dlm replikasi DNA mampu menyebabkan perubahan pada sifat sel anakan. Terdapat tiga model mekanisme replikasi DNA, yakni 1. Model konservatif Kedua untai polinukleotida induk atau yag usang tak berubah & berfungsi sebagai cetakan. Makara, heliks ganda DNA gres tak mengandung polinukleotida lama. 2. Model semikonservatif Kedua untai polinukleotida berpisah, lalu masing-masing membuat untai polinukleotida baru selaku pelengkap. Jadi, diperoleh dua heliks ganda DNA yg masing-masing mengandung satu untai polinukleotida lama & satu untai polinukleotida gres. 3. Model dispersif Beberapa serpihan kedua untai polinukleotida usang dengan-cara tersebar berfungsi selaku cetakan, kemudian masing-masing serpihan membuat belahan-serpihan polinukleotida baru sebagai pelengkapnya. Jadi, diperoleh dua heliksa gada DNA yg masing-masing mengandung molekul DNA usang & DNA baru dengan-cara berselang-seling pada kedua untai polinukleotida. Pembahasan Model struktur molekul DNA dikemukakan oleh James Watson & Francis Crick pada tahun 1953. DNA mempunyai struktur heliks ganda double helix berpilin & diilustrasikan sebagai tangga tali terpilin ke arah kanan. Struktur DNA yg double heliks yakni suatu polimer yg terdiri dr nukleotida-nukleotida. Nukleotida yg tak mempunyai gugus fosfat disebut nukleosida atau deoksiribonukleosida. Nukleosida merupakan prekursor dlm sintesis DNA. Tiap nukleotida terdiri atas 3 komponen yaitu Gula pentosa deoksiribosa ribosa yag kehilangan satu atom oksigenya Gugus fosfat PO₄⁻ Basa nitrogen, yg terdiri dr dua jenis sebagai berikut Purin, ada dua macam yaitu guanin G & adenin A Pirimidin, ada dua macam yakni timin T da sitosin S/C Struktur heliks gada DNA mampu diilustrasikan sebagai tangga tali berpilin. Fosfat dr sebuah nukelotida akan membentuk ikatan fosfodiester degan gula dr nukleotida berikutnya. Ikatan gula dgn fosfat diilustrasikan selaku tulang belakang gula fosfat atau ibu tangga. Sementara itu, basa nitrogen purin pada suatu nukleotida akan membetuk ikatan hidrogen sebagai pasangan tetap dgn pirimidin dr nukleotida lainya. Ikatan basa purin-pirimidin diilustrasikan selaku anak tangga. Ikatan hidrogen yg dibuat adenin denga timin ialah dua ikatan hidorgen A=T, sedangkan guanin dgn sitosin membentuk tiga ikatan hidrogen G≡C. Bagan struktur DNA berdasarkan Watson & Crick dapat dilihat pada gambar dibawah. Kesimpulan Berdasar penjelasan diatas, dapat disimpulkan bahwa struktur DNA berdasarkan Watson & Crick yakni heliks ganda double helix berpilin yg terdiri dr nukleotida-nukleotida. Pelajari lebih lanjut 1. DNA tambahan & sintesis protein 2. ikatan hidrogen pada DNA 3. kiprah DNA dlm encoding Detil Jawaban Kelas 3 SMA Mata pelajaran Biologi Bab Materi genetik Kode Kata kunci DNA, struktur DNA menurut Watson & Crick WIKIPEDIA DUA peneliti dari Universitas Cambridge, James D Watson dan Frances H C Crick, hari ini pada 1953 mengumumkan mereka sudah menemukan struktur helix ganda deoxyribonucleic acid DNA, molekul yang mengandung gen manusia. Meskipun DNA ditemukan pada 1869, fungsi utama yang menentukan warisan genetik tidak dijelaskan sampai 1943. Pada awal 1950-an, hanya Watson dan Crick yang meneliti struktur DNA. Mereka menemukan bahwa struktur DNA ialah polimer helix ganda atau spiral dari dua untai DNA. Keduanya mengandung rantai panjang monomer nukleotida, terpilin satu sama lain. Menurut hasil penemuan mereka, DNA mereplikasi diri dengan memisahkan diri menjadi untai tunggal, masing-masing akan menjadi wadah untuk dua helix Baca Juga Asam Amino dalam Bumbu Umami Bantu Lansia Tingkatkan Kualitas Hidup 👤Media Indonesia 🕔Kamis 15 Juni 2023, 1323 WIB Karena faktor usia membuat hormon-hormon pengatur selera makan pada lansia cenderung menurun sehingga berpotensi menyebabkan... Ini Dia 10 Khasiat Jus Mentimun Campur Wortel untuk Kesehatan 👤Meilani Teniwut 🕔Kamis 15 Juni 2023, 1250 WIB Kombinasi wortel dan mentimun yang kaya akan nutrisi dipercaya dapat mengurangi kadar asam urat dalam tubuh. Tidak hanya asam urat adapun... Donor Darah Dipastikan Selamatkan Nyawa Banyak Orang 👤Basuki Eka Purnama 🕔Kamis 15 Juni 2023, 1230 WIB Donor darah juga bermanfaat bagi diri sendiri, karena dapat menstimulasi organ sumsum tulang belakang pada tubuh untuk membuat darah yang... IntroductionThe remarkable structure of deoxyribonucleic acid DNA, from the nucleotide up to the chromosome, plays a crucial role in its biological function. The ability of DNA to function as the material through which genetic information is stored and transmitted is a direct result of its elegant structure. In their seminal 1953 paper, Watson and Crick unveiled two aspects of DNA structure pairing the nucleotide bases in a complementary fashion adenine with thymine and cytosine with guanine and the double-helical nature of DNA.[1]Their proposed model for DNA structure explained previous observations, such as the equivalent ratios of purines and pyrimidines found in the DNA molecules.[2][3] It also provided a framework for the subsequent elucidation of the mechanism involved in DNA replication. Issues of ConcernThe primary issue of concern regarding the DNA structure is variations and mutations in DNA structure as proteins encoded by the mutated DNA generally have altered structure and function, adversely impacting the survival of the cell or organism. Mutations in DNA structure can take many forms, such as large or small insertions or deletions of base pairs or inversions and insertions of whole DNA segments between or within chromosomes.[4] In addition, several disorders are due to defects in cellular mechanisms associated with DNA, including replication, DNA repair, and transcription.[5][6][5][7]Cellular Level One significant difference between prokaryotes' and eukaryotes' DNA structure is that prokaryotic DNA molecules are circular and thus do not have free 5' and 3' ends. Circular DNA molecules are also found in eukaryotic mitochondrial and chloroplast DNA, evidence that supports the endosymbiotic theory of eukaryotic evolution.[8] In contrast, the ends of eukaryotic DNA molecules do not connect and are thus "free." Prokaryotes typically have one main circular chromosome, while eukaryotes have multiple linear chromosomes of varying sizes. For the specific purpose of decreasing their DNA size to ensure fitting inside a cell, prokaryotes employ DNA supercoiling.[9]However, because eukaryotes have much more DNA than prokaryotes 3234 mega-base pairs vs. mega-base pairs, they need to utilize a more complex strategy to position their DNA, which, if stretched from end to end, would be two meters long, properly inside a microscopic cellular space.[10] Specifically, this is done by sequential levels of coiling, starting with DNA wrapping around histone proteins forming a structure known as a nucleosome, then nucleosomes coiling to form chromatin fibers, and then chromatin further condensing into densely packed chromosomes.[11]Molecular Level A molecule of DNA is made up of two long polynucleotide chains consisting of subunits known as nucleotides. A nucleotide comprises a nitrogenous base, a pentose sugar, and at least one phosphate group Figure 1a.[12] In the case of DNA, the sugar is 2’-deoxyribose, and thus it has no hydroxyl group attached to its 2’ pronounced “two prime” carbon; this is in contrast to ribose sugar in RNA, which does not have the 2’ position of its pentose sugar to be reduced or deoxygenated. A phosphate group covalently binds to the 5’ carbon of 2’-deoxyribose. Since the 2’-deoxyribose and the phosphate group are always present, the nitrogenous bases they incorporate distinguish the four DNA nucleotides.[13]A nucleotide can incorporate four main nitrogenous bases, two of which are purines and two that are pyrimidines Figure 1b. Both purines and pyrimidines are heterocyclic aromatic compounds, as they contain nitrogen atoms in their carbon-based ring, which are essential for the hydrogen bonding that holds the two strands of the DNA molecule together. However, while pyrimidines are six-membered rings, purines consist of a five-membered ring fused to a six-membered ring. The two pyrimidines found in DNA are thymine T and cytosine C, while the two purines are Adenine A and Guanine G. The purines and pyrimidines differ slightly in structure, but their functional groups are attached to the same basic heterocyclic form. These nitrogenous bases are covalently bonded via a nitrogen atom to the 1’ carbon of the deoxyribose sugar in a nucleotide Figure 1a.[1]Although four major nitrogenous bases make up the nucleotides of DNA, other uncommon non-primary or modified bases have been found to exist in nature.[14] The most common modified bases in bacterial genomes are 5-methylcytosine, N6-methyladenine, and N4-methylcytosine. These modifications have been shown to protect DNA from restriction enzymes, which cleave DNA at specific sites. In all eukaryotic genomes, the most common modified base is 5-methylcytosine which is critical in regulating gene expression.[15]Each strand of DNA is made up of a string of nucleotide subunits linked at their sugar moieties Figure 2a. Specifically, nucleotides in a DNA strand are bound together via ester bonds between the phosphate group attached to their 5’ carbon and the hydroxyl group on the 3’ carbon of an adjacent nucleotide. This bond is known as a phosphodiester bond, and it forms via a condensation reaction during DNA synthesis. As a result, each strand of a DNA molecule has a series of nucleotides with their 5’ phosphate and 3’ hydroxyl group participating in phosphodiester bonds. Each strand of a eukaryotic DNA molecule has a “free” 5’ phosphate group on one end, not bonded to a hydroxyl group, and a “free” 3’ hydroxyl group on the other end, not bonded to a phosphate group. This asymmetry has led to the adoption of the convention where DNA is read in a particular direction, from its 5’ end to its 3’ end. The sequence of nucleotides that make up a molecule of DNA is referred to as its primary structure.[16]A DNA molecule consists of two chains of polymerized nucleotides running side-by-side, joined together by hydrogen bonds forming between their nitrogenous bases Figure 2a. Notably, the nucleotides bond in a particular fashion, with A pairing with T and G pairing with C; A and T pairing is by two hydrogen bonds, and C and G by three. These specific pairings result in about a 1 to 1 ratio of pyrimidines and purines in any given cell, a concept known as Chargaff’s rule. This pairing scheme is called complementary base-pairing and is the most energetically favorable pairing possible. DNA is structured so that the sugars of each strand are on the outside, while the bases hydrogen bond on the inside, resulting in what is known as the sugar-phosphate backbone. Thus, two chains of sugar-phosphate backbones run side-by-side with complementary paired nitrogenous bases hydrogen bonding between them. Notably, the two strands of a DNA molecule run in an antiparallel fashion so that the 5’ end of one strand is the 3’ end of the other.[17] This base pairing of nucleotides between the two strands of a single DNA molecule is called DNA’s secondary three-dimensional shape of a DNA molecule, or its tertiary structure, is a right-handed double helix Figure 2b. The hydrogen-bonded bases on each strand are stacked in parallel and run perpendicular to the sugar-phosphate backbone. As indicated by its x-ray diffraction pattern, the bases are regularly spaced at nm apart along the axis of the helix.[18] Additionally, there are about ten pairs of bases per turn, as a complete turn of the helix is made every nm. DNA has a +36-degree rotation per base pair bp and a helical diameter of nm.[18] When focusing on the backbone of the DNA helix, two helical grooves exist with different widths, known as the minor and major grooves Figure 2b. The minor groove describes the space between the two antiparallel DNA strands that run closest together, while the major groove describes the space where they are furthest apart. These specific dimensions describe the B form of DNA, the major form present in most stretches of DNA in a cell.[19] This is in contrast to DNA’s much rarer A and Z forms. The A form is a right-handed double helix with less distance between the bases nm, and thus more bases per turn 11 bp per turn and a smaller helical rotation per base pair +33 degrees.[19][20] Z DNA is a left-handed double helix and is most present in the human genome, where many purines and pyrimidines are alternating in succession in a sequence such as GCGCGCGCGCG.[20] DNA primarily takes the B form, in contrast to any other form, because it is the most energetically stable tertiary structure.[20][21]A notable property of DNA is the ease of reversible separation of its two strands due to hydrogen bonds being relatively weak compared to covalent bonds. This is important because fundamental cellular processes such as DNA replication and RNA transcription rely on proteins accessing individually separated strands of DNA. Thus, during these processes, proteins known as helicases move down the DNA molecule and unwind the two strands by disrupting the hydrogen bonding between bases. However, when the cellular processes requiring strand separation are complete, the complementary strands can easily re-anneal. This property of reversible separation can be experimentally induced via the heating and cooling of a DNA molecule and is referred to as denaturation or “melting.”[22][23]One notable structural phenomenon of DNA tertiary structure is supercoiling, or the coiling of the larger, already coiled DNA molecule. Specifically, in a DNA molecule that has its ends fixed, such as in the circular DNA found in prokaryotes or the smaller DNA segments that make up a larger chromosome in eukaryotes, separation of the individual strands of DNA during cellular processes causes the DNA to twist-up past the points of strand separation, leading to strain on the larger DNA structure.[9] This transient over-winding of the larger DNA structure when separating individual strands is known as positive supercoiling Figure 5. Every cell has enzymes that keep DNA actively underwound to compensate for this, resulting in perpetual negative supercoiling, where the larger DNA structure coils in a left-handed fashion. This results in the strands of DNA needing less energy to be separated and keeps the molecule primed for easy separation in the events of transcription and DNA replication. FunctionThe unique structure of DNA is ultimately responsible for its function as being the material that stores and transmits genetic information from one generation to the next. Specifically, the four nitrogenous bases that comprise the sequence of nucleotides in a DNA molecule enable an enormous amount of information stored in minimal space. DNA’s sugar-phosphate backbone and helical structure make it more stable, less prone to damage, and more compact; however, the hydrogen bonds that hold the strands of DNA together make it more accessible for its biological functions as they are individually weak but cumulatively strong. Also, the complementary base pairing of nucleotides in DNA enables accurate semiconservative replication as each strand carries identical genetic information and serves as an independent template during DNA replication.[13][24]Clinical SignificanceDNA mutations have a fundamental role in the pathophysiology of multiple conditions ranging from congenital and developmental diseases to cancer.[25][26] One important example is sickle-cell anemia, an inherited genetic disease that predominates in individuals of African descent. This disease is a direct result of a single point mutation of an A to a T in the gene that encodes beta-globin, resulting in the sixth amino acid in beta-globin’s polypeptide chain changing from glutamic acid to valine.[27] Consequently, an individual homozygous for this mutation will have hemoglobin with mutated beta-globin subunits, known as HbS, that aggregate into crystalline arrays when deoxygenated. This mutation in hemoglobin results in the deformation of erythrocytes into a sickle-like shape, making them prone to block capillaries, leading to hemolytic anemia, episodes of vascular occlusion, and reduced blood flow.[27][28]Review QuestionsFigure1a Structures of DNA nitrogenous bases 1b General structure of a DNA nucleotide 2a Hydrogen bonding between two pairs of complementary nucleotides in a DNA molecule 2b B-DNA structure and characteristics. Contributed by Jack Ghannam JD, CRICK FH. Molecular structure of nucleic acids; a structure for deoxyribose nucleic acid. Nature. 1953 Apr 25;1714356737-8. [PubMed 13054692] KL. Historical opinion Erwin Chargaff and his 'rules' for the base composition of DNA why did he fail to see the possibility of complementarity? Trends Biochem Sci. 2008 Feb;33265-70. [PubMed 18207747] CC, GAFFORD LG, DARLINGTON RW. Bases of the nucleic acid of fowlpox virus and host deoxyribonucleic acid. J Bacteriol. 1962 May;8351037-41. [PMC free article PMC279405] [PubMed 14490218] N, Rabbani B. An overview of mutation detection methods in genetic disorders. Iran J Pediatr. 2013 Aug;234375-88. [PMC free article PMC3883366] [PubMed 24427490] R, Boulton SJ. Spotlight on the Replisome Aetiology of DNA Replication-Associated Genetic Diseases. Trends Genet. 2021 Apr;374317-336. [PubMed 33041047] M, Nyström M, Peltomäki P. Disorders of DNA repair mechanisms and their clinical significance. Duodecim. 2017;1333259-5. [PubMed 29205024] TI, Young RA. Transcriptional regulation and its misregulation in disease. Cell. 2013 Mar 14;15261237-51. [PMC free article PMC3640494] [PubMed 23498934] JM. Endosymbiosis and Eukaryotic Cell Evolution. Curr Biol. 2015 Oct 05;2519R911-21. [PubMed 26439354] J, Wang MD. DNA supercoiling during transcription. Biophys Rev. 2016 Nov;8Suppl 175-87. [PMC free article PMC5338639] [PubMed 28275417] M, Langston L, Stillman B. Principles and concepts of DNA replication in bacteria, archaea, and eukarya. Cold Spring Harb Perspect Biol. 2013 Jul 01;57 [PMC free article PMC3685895] [PubMed 23818497] B, Tupper C, Al Aboud NM. StatPearls [Internet]. StatPearls Publishing; Treasure Island FL Jun 5, 2022. Genetics, DNA Packaging. [PubMed 30480946] FB. The biochemistry and physiology of nucleotides. J Nutr. 1994 Jan;1241 Suppl124S-127S. [PubMed 8283301] A, Muskhelishvili G. DNA structure and function. FEBS J. 2015 Jun;282122279-95. [PubMed 25903461] S, Chinnusamy V, Mohapatra T. Epigenetics of Modified DNA Bases 5-Methylcytosine and Beyond. Front Genet. 2018;9640. [PMC free article PMC6305559] [PubMed 30619465] VR, Jarmasz JS, Murugeshan N, Del Bigio MR, Rastegar M, Davie JR. DNA modifications function and applications in normal and disease States. Biology Basel. 2014 Oct 22;34670-723. [PMC free article PMC4280507] [PubMed 25340699] IR. DNA ligase structure, mechanism, and function. Science. 1974 Nov 29;1864166790-7. [PubMed 4377758] M, Pedzinski T, Czapik T, Kierzek E, Kierzek R. Structural Aspects of the Antiparallel and Parallel Duplexes Formed by DNA, 2'-O-Methyl RNA and RNA Oligonucleotides. PLoS One. 2015;1011e0143354. [PMC free article PMC4666348] [PubMed 26579720] G, Damaschun H, Misselwitz R, Pospelov VA, Zalenskaya IA, Zirwer D, Müller JJ, Vorobev VI. How many base-pairs per turn does DNA have in solution and in chromatin? An answer from wide-angle X-ray scattering. Biomed Biochim Acta. 1983;426697-703. [PubMed 6639645] JB, Dattagupta N, Crothers DM. Studies on interaction of anthracycline antibiotics and deoxyribonucleic acid equilibrium binding studies on interaction of daunomycin with deoxyribonucleic acid. Biochemistry. 1982 Aug 17;21173933-40. [PubMed 7126524] RE, Drew HR, Conner BN, Wing RM, Fratini AV, Kopka ML. The anatomy of A-, B-, and Z-DNA. Science. 1982 Apr 30;2164545475-85. [PubMed 7071593] A, Cooper DN, Vasquez KM. DNA structure matters. Genome Med. 2013;5651. [PMC free article PMC3706936] [PubMed 23796271] W, Spencer WJ, Rhoads RE. Optimization of the annealing temperature for DNA amplification in vitro. Nucleic Acids Res. 1990 Nov 11;18216409-12. [PMC free article PMC332522] [PubMed 2243783] B, Bleichert F. Origins of DNA replication. PLoS Genet. 2019 Sep;159e1008320. [PMC free article PMC6742236] [PubMed 31513569] R, Khaddour K. StatPearls [Internet]. StatPearls Publishing; Treasure Island FL May 8, 2022. Biochemistry, DNA Replication. [PubMed 29489296] J, Zaidi S, Shen Y, Ware JS, Samocha KE, Karczewski KJ, DePalma SR, McKean D, Wakimoto H, Gorham J, Jin SC, Deanfield J, Giardini A, Porter GA, Kim R, Bilguvar K, López-Giráldez F, Tikhonova I, Mane S, Romano-Adesman A, Qi H, Vardarajan B, Ma L, Daly M, Roberts AE, Russell MW, Mital S, Newburger JW, Gaynor JW, Breitbart RE, Iossifov I, Ronemus M, Sanders SJ, Kaltman JR, Seidman JG, Brueckner M, Gelb BD, Goldmuntz E, Lifton RP, Seidman CE, Chung WK. De novo mutations in congenital heart disease with neurodevelopmental and other congenital anomalies. Science. 2015 Dec 04;35062651262-6. [PMC free article PMC4890146] [PubMed 26785492] G, Ke E, Aziz M, Liarakos D, Tong M, Stites EC. Cancer gene mutation frequencies for the population. Nat Commun. 2021 Oct 13;1215961. [PMC free article PMC8514428] [PubMed 34645806] PA. Sickle cell disease. Pediatr Clin North Am. 1996 Jun;433639-64. [PubMed 8649903] A, Ehsan M, Agarwal N, Maruvada S. StatPearls [Internet]. StatPearls Publishing; Treasure Island FL Nov 30, 2022. Sickle Cell Anemia. [PubMed 29489205]Disclosure Jack Ghannam declares no relevant financial relationships with ineligible Jason Wang declares no relevant financial relationships with ineligible Arif Jan declares no relevant financial relationships with ineligible companies.

jelaskan struktur dna dengan bagan menurut watson dan crick