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EE —— Xx CUNIT a) KY Octo Pane 6) CBlocHEMI Y NUCLEIC ACID ) Essenbal_marcomolecuies tat carry genetic information:and plays G crodal role in all Known life forms oF UFe- Responsible for stonng , transmitting and expressing geuetic instwctions. LEY 4 g€ The Building Blocks 3 Nucleoside and Nucleo ticles The Fundameutal units oF nucleic acids qre called nucleotide IE is composed of. 3 main parts : @ Nitrogen base @) 5 carbon sugar chain @ one or more puosphate group Bulding blocks of PNA and RNA lee Para ae Se rea i ag c N=B=-Qlycosidic linkage Phosphate bond Poane = Ci sugan - Ng base Py mini e- CT 60gaT= NT ba Lcin nucleoside) A nucleoside congist only oF a nitrogen base anda $- carbon Sug + withour tne Phosphate Zioup ———— Nttz ° i Ti N nt (own fi ) i) Cerne AeoKynvose in DNA or Ribose tn RNA 4+ets—- Seo ee eeeeescerresce J —— y Y Page, Nitrogencus Base : Hetracyclic compound contaning Nitrogen L@) _ Pusines © Double ang shucture | 3 &: Adenine (AD Gaunine (G6) L(G) sine Pyaimidines 3 single sing Structure ex : cywsine (c) « Ural Cadin RNA and Thymine (7) 9RPRDIR BAX in DNA (2) S— carbon Sugar + @) Deorynbose 2 Found in PNA La © LACKS Oxygen atom at the a! carbon pohition oe __||_@) Ribose 3 Foundin RNA © (t has a nydroxyl group (-OHJat aind __ carbon position. qa toa “n “ THIOCHZ U ~f ae l ae AN H/H Z | = OH H J deoxy a bose Ribose | phosphate gop : -ve charged group that linked nocleotides togetnertefarm the uucielc latid backbone PFpvrrvrerrere. | > 2a id | PnesPhodiester unkage: oe a | They me liked together to Porm @ ong polynucleohde aur hes eS ar — |cnain uiq prosplro diester UnKxse — OFT oLL It is formed vw “S$! -phosplate group of o' maclect? fo HE Bi- hydroxyl Qaoup 4 wext uucleodide. \ CHa 0 sate) ‘ir a I H\4 H/H L 3 - | of H Onosphate- Unkage L i — y ! aX, cdiesten ] | (oS Fe =O } ee i fe) a? © creats q backbone i 4 Csvgon- phosphate) CHz ee) em 7 o pirectional , with free q a GH. HJ S$! —pnosphate ¢eoup ye Wo 3! nyaroxy qaoup OH H M OMA r2trol DNA STRUCTURE 32 THE WATSON CRICK MODEL. praarerere rrr eereTI—IIIVIV? UY Desanbe SNA as a double helix model | yy Y 2 @egeesssse aa 7 KEM FEATURES } 9 TWO tteltea DNA chains b DNA molecule congist OF A tong poly -nucleotide chaing wound around the same — oriticalaxls. b {bis in n Right handed Postion Hydro prilic Backbone On the duteide . ae sugar — phosphate backbone which are nyolrophi ttc due 10 charged phosphate group are tocated of outsicle . This, anangmeut 4 Allows then to inlenact with the Saasounding water WUoleCLLes. | | | imenraity uiltuin the double bouuded peux. SSECCCEE Anhpaniel Stand6 : The A DNA BHand ru in the opposite direction {ff ane Strand runs S'to 3' and othen to 3! 40 s? S666 6 Speake Base painng (chargaffis Rue) Adenine (A) always pairs with Thymine (T) via 2 Hydrogen Ay bond l ¢ Gvanine (6) always pair wi Cytoxine CO via & yetrogen | aa | x | The greater no. oF H ater bonds bilw G and C smaes G2 Men pegiau wore stable and harder bo seprate thour A=T acts TOI, SSeS ESE om te b | | | wet | _Vanablity g Flexiblity of ONA DNA IS not @ rigid r static molecule vaaiablity ane Hexipuity. AE wWexld BIE Structure) a | no vree / Mt DNA Backbone Fler otiry is Infivenced by rotation around 7 dit. bonds 6 of these bonds can rotate freely The ti vond (ie t4t) within te Furanose (s-meubened ving) —- one . [has limited rotation. ~~ | Sugar Pucker ™y b Limited Rotahon Abaut bond 4 give vise 10 Phenomencne dl cauled sueer pucker ving - Le one of tne atoms In $ wemben 8092 zing is displaced oot i oF he plane descriven by me othen 4 atums. ea Endo conformation éxo conhYmation — alsplaced atomis on 2 dAlsptaced atumis on the same Side of the plane tre opp- Fide OF) the plane as. C-$ atom from the C-s aug i i Abase “3 a = ae Tt one a | gg CoA endo exo iipadalsyoedaah } Glycomdic Bond Coufyuwaheu the bond linking the nierog@ NOUS base fo me. sugar iS Called te N-glycosidic bond. This bond also has rotational Hexibliry 1 ——— 332223 which affects the onentation 0) the bases relanve te the sugar. | CENTRAL DOGMA ANDTHE CLNETIC FLOW The general fiow geuttic Info - DNA rs RNA PROTEIN Zs Repticati on CONA to DNA) PNA can repli ate jtselt through 9 semi -consenvative replication » meaning each new PNA morecule consit of one synmesised Shand and one origned EE ea ee enseres his eequseds accamate transmission of te geurtic information frou one generation to anotha. tranczipnon * DNA infoxmaton encoded in DNA is franscy -bea into an RNA molecule & Ws ANA Strand ts complementary fe ane 6) me DNA Strands, a Translation 2 The RNA coc salen the genetic code — from PNA to The yibosonjen ¢ here tt is hanwiatedt inte a sequence 4 oumlnd adds ifooming — a padbeln- a arraareeererrzr7TTTr397t? oma sien, | back on itsey 1 ith complementary base> pining ro fe : | and intervening unpalredl bases to form @ loop. ¥ “er ltlslelejairfa ct clalriclech) _ , a ee Tr EC ld : “a. ey ¢c T __ ee - ——_—_. i a a tal \7 [= K T - + —_—___ 64+ te a ¢ 6 ; | L : i G ~ - 7 BK gig L =o | : i | Cruciform 4, Forms when both strands of @ duplex DNA 16 | involved 4 AF q palindormic Sequence exist on both strands of ] A double helix » each Strand Can form a haspin ldap | Structure resulting 1. cross Or conform Structu re | g_ “Atiédelaltic + talthelelel Ab kas Ge a en eo ee ae Se ee Piast a) a = T 4 i ) ae Alclelc/7TAlG a |r Al Giclelt | Sere : ieee || pall = > [sae _ € G | » 6 —-¢ 5 _ th a sf a! ae T TT Fi Sit La | Aeere ae lial ——— —~ 6G G — | — lo 6 = ne * | ie T | S steesh me , it Je | Gg >| ON + REANNEALING AND HYBRIDIZATION fs psec io a — - i The ddhelical stucture of DNA can be reversibly seprated or ffommed . Denaturation, refers to Sepration of tne & complementary Strands #f& Double heix ofa ONR Causes 2 can be induced by vasioUS factors that distrupt eesereeercors eres Ee | ‘ SE — ae ) | Dependance on Base composition _ . | Tm oh of oF G-C base pails « eet | DF e-ceentent ot tm > |__ BB bez G-C paiys ale held together by @ hydrogen bonds > maiivy tum mor steele aud mquirivy wore CL gS » . es >—— Reannealing (Renatwrahan ) ad The process whene sepreated single strands OF DNA S pontaneo ust » come baur togeM +o sefoxm Q ouble helix - ~~ , ~~ Condition: occu% au aenatusing comditiaus On & reuLers ed _ (eq -4t tewp ) The complentouly nasa pais Find eachotu4 colly te gale fre baa tivy to rejomm, ~~ = Kinetics : » The wate of renatuation depends OM tL conc. 5) DNA = and the complex tty % genome ~ 3 — ; —y More complex genome —~——_ ong Mme fo rennea) | __ ver mney are md Vv =— 2 more onique SyULeNS, = 7 i mating (6 nerol Far ~~ complemexstany Strand to Fr/ = Cack oft. ] ‘ ' a = Sasol -— ) Sw (ou —___ as (CSE PpPRAaE HYBRIDISATION x Specific tyre OF teanneating whenea complementary yy | | nucleic acid Strands (which an be DNA-DNA , DNA RNA, Or RNA-RNA) Come together to form a Stable clouble - Standed hybsid molecule i Basis for Techniques . The abliky af DNA sequence jo spontanéously reannel and tem helic& is the fundamental basis for many, melecutan biology techniques, Including: opcR . PaimeS (enort DNA seq.) hy nrdize to tary er DNA regiong 2 DNA Seqendng: Relea om me hybroizanon of DNA fragments © southern / Nort vlols 1 probes (\ ed eLed wdc acid Se@yvents) hybewtdize to target bw FP or RNA Yegions Moniforing Rehaturahon Kinetics often plotted AF aS conc. X Hme Wrve 2 |Iprovide insignts tate genome compiexi'ty, IG can be monitored in a ways, a. || Decrease in Absorbance at a60 nm arrpPpPperervrev ere 22929222 (typercnromic effects): a single stranded DNA teay te, 
