Thefunctionand several classesofRNAribosomalRNAs(rRNAs)=componentsofribosomes-messengerRNAs(mRNAs)=intermediatesinprotein synthesistransferRNAs(tRNAs)=adaptermoleculesthat translatethe information inmRNAintoaspecific amino acid sequencenoncodingRNAs(ncRNAs)=widevarietyoffunctions
The function and several classes of RNA
NucleotidesandNucleicAcidsHaveCharacteristicBasesandPentosesnucleotideshavethreePurine orcomponents:pyrimidinebaseanitrogenousbasePhosphate(pyrimidine orPentosepurine)-apentoseOHOH(a)-1+phosphatesnucleoside=theHCHCmoleculewithouta(b)PurinePyrimidinephosphate group
Nucleotide Nitrogenous Basesmajor purine bases:-adenine(A)=inDNAand RNA- guanine (G)= in DNAandRNAAdenineGuaninePurinesmajorpyrimidine bases:-cytosine(C)=inDNAandRNAthymine (T) = only inUracilCytosineThymineDNA(RNA)(DNA)Pyrimidinesuracil(U)=onlyinRNA
NucleotideandNucleicAcidNomenclatureTable 8-1 Nucleotide and Nucleic Acid NomenclatureBaseNucleosideNucleotideNucleic AcidPurines:RNAAdenosineAdenylate碱基名称英文全称读音DNAAdenineDeoxyadenosineDeoxyadenylate腺嘌岭Adenine/'aedani:n/Purines:RNAGuanylateGuanosineGuanineDeoxyguanosineDNADeoxyguanylate胸腺嘧啶Thymine/eaimi:n/Pyrimidines:CytidineCytidylateRNADNACytosineDeoxycytidineDeoxycytidylate鸟嘌岭GuanineI'gwa:nin/Pyrimidines:ThymidineorThymidylateordeoxythymidylateDNA胞嘧啶Cytosine/'sartasi:n/ThyminedeoxythymidinePyrimidines:UridineUridylateRNAUracil
Nucleotide Pentosestwokinds ofpentoses:E-2'-deoxy-d-ribose=OHin DNA-OHH-OHD-ribose=inRNA5CH2OH(a)Aldehydeβ-Furanoseboth areintheirβ-furanose(closedfivemembered ring)form