河南农业大学：《生物化学》课程PPT教学课件（本科双语教学）第六章 含氮化合物代谢 Nucleotides and Nucleic Acids

Chapter 6 Nucleotides and Nucleic Acids Francis Crick and James Watson point out features of their model for the structure of DNA

Chapter 6 Nucleotides and Nucleic Acids Francis Crick and James Watson point out features of their model for the structure of DNA

deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)

deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)

DNA Repllcadon 0000 DNA replicntion yields two DNA molecules identcl to the original one,ensuring transmiaion Replicatlon of genetic information to daughter cells with exceptional fidelity. Transcription The sequence of bases in DNA is recorded as a sequence of complementary hases in a single- stranded mRNA molecule. mRNA ERNAS Translatioo Trandladoa Three base codons on the mRNA mRNA corresponding to specific amino acids direct the sequence of building a protein.These codons are recognized by tRNAs (transfer RNAs)carrying the appropriate amino acids.Ribosomes Attached are the "machinery"for procein amino acid 由ek Growing peptide chain

6.1 Nitrogenous Bases NHg H H H Adenine (6amino purine) (2-amino-6-osy purine) Uric acid

6.1 ·Nitrogenous Bases

NH2 Nitrogenous bases N Bicyclic purines Adenine(A) Guanine (G) Monocyclic pyrimidine Cytosine(C) Uracil (U;R=H) Thymine(T;R=CHa) Thymine(T)is 5-methyluracil(U)

Nitrogenous bases Bicyclic purines: Monocyclic pyrimidine: Thymine (T) is 5-methyluracil (U)

Comparisons of names of bases,nucleosides and nucleotides BASES NUCLEOSIDES NUCLEOTIDES Adenine (A) Adenosine Adenosine 5'-triphosphate(ATP) Deoxyadenosine Deoxyadenosine 5'-triphosphate(dATP) Guanine (G) Guanosine Guanosine 5'-triphosphate(TP) Deoxy-guanosine Deoxy-guanosine 5'-triphosphate(TP) Cytosine (C) Cytidine Cytidine 5'-triphosphate(C1) Deoxy-cytidine Deoxy-cytidine 5'-triphosphate(P) Uracil (U) Uridine Uridine 5'-triphosphate (UTP) Thymine (T) Thymidine/ Thymidine/deoxythymidine deoxythymidine 5'-triphosphate(dTTP) Purine:A G;Pyrimidine:C&T/U;(deoxy)-ribose

BASES NUCLEOSIDES NUCLEOTIDES Adenine (A) Adenosine Adenosine 5’-triphosphate (ATP) Deoxyadenosine Deoxyadenosine 5’-triphosphate (dATP) Guanine (G) Guanosine Guanosine 5’-triphosphate (GTP) Deoxy-guanosine Deoxy-guanosine 5’-triphosphate (dGTP) Cytosine (C) Cytidine Cytidine 5’-triphosphate (CTP) Deoxy-cytidine Deoxy-cytidine 5’-triphosphate (dCTP) Uracil (U) Uridine Uridine 5’-triphosphate (UTP) Thymine (T) Thymidine/ deoxythymidine Thymidine/deoxythymidine 5’-triphosphate (dTTP) Comparisons of names of bases, nucleosides and nucleotides Purine: A & G; Pyrimidine: C & T/U; (deoxy)-ribose

6.2 The Pentoses of Nucleotides and Nucleic Acids H d HOCH: OH H-C-H HOCH 0 OH OH H H-C-OH H H H H- C-OH OH OR H-C-OH OR H HCOH Furanoee form of HCOH Furanose form af D Ribose n2-Deaxyribose bRihose 3-p-Ribofurnose p-2-Deoxyrihos B-p-2-Deoxyribofuranobe Furanose structures-ribose and deoxyribose

Furanose structures—ribose and deoxyribose. 6.2 The Pentoses of Nucleotides and Nucleic Acids

6.3·Nucleosides Are Formed by Joining a Nitrogenous Base to a Sugar

6.3 ·Nucleosides Are Formed by Joining a Nitrogenous Base to a Sugar

HOCH H OH OF加 B-N:glycouidie hond in pyrimldloe diboeueleeaides HOCH。 H H H OH OH B-Ne内cosidic boad鱼pune Hboaueleosides

NHg H HOCH HoCH o. HOCH2 H H H H H H OH OH OHOH OH OH Cytidine Uridiae Adenoalne H HOCH: HOCH KH H H H H H OH OH OH OH Gusnosine Inosine,an uocommon nucleoside