Presentation is loading. Please wait.

Presentation is loading. Please wait.

Nucleotides & Nucleic Acids

Published byKevin Carroll Modified over 6 years ago

Similar presentations

Presentation on theme: "Nucleotides & Nucleic Acids"— Presentation transcript:

1 Nucleotides & Nucleic Acids
Page 325 Chapter 10 Nucleotides & Nucleic Acids

2 Nucleic acids: linear polymers of nucleotides
Page 325 Nucleic acids: linear polymers of nucleotides linked 3’ to 5’ by phosphodiester bridges (bond) ---DNA (deoxyribonucleic acid) ---RNA (ribonucleic acid)

3 Page 326

4 =nucleoside + phosphate
=base + sugar

5 What Are the Structure and Chemistry of Nitrogenous Bases?

6 Page 325 Nitrogenous Bases

7 Pyrimidine Page 326 Purine

8 Three Pyrimidines Are Commonly Found in Cells
Page 326 & 327 The common pyrimidine bases – cytosine, uracil, and thymine – in the tautomeric forms predominant at pH 7.

9 Two Purines Are Commonly Found in Cells
Page 326 & 327 Figure The common purine bases – adenine and guanine – in the tautomeric forms predominant at pH 7.

10 Page 327 Figure Other naturally occurring purine derivatives – hypoxanthine, xanthine, and uric acid.

11 Tautomerization Page 327 The aromaticity of the pyrimidine and purine ring systems and the electron-rich nature of their carbonyl and ring nitrogen substituents endow them with the capacity to undergo keto–enol tautomeric shifts.

12 Tautomerization Page 327

13 Page 327

14 Page 328 Another property of pyrimidines and purines is their strong absorbance of ultraviolet (UV) light, which is also a consequence of the aromaticity of their heterocyclic ring structures.

15 Page 328

16 The Properties of Pyrimidines and Purines Can Be Traced to Their Electron-Rich Nature
Page 326 & 327 The aromaticity and electron-rich nature of pyrimidines and purines enable them to undergo keto-enol tautomerism The keto tautomers of uracil, thymine, and guanine predominate at pH 7 By contrast, the enol form of cytosine predominates at pH 7 Protonation states of the nitrogens determines whether they can serve as H-bond donors or acceptors Aromaticity also accounts for strong absorption of UV light

17 What Are Nucleosides?

18 Nucleoside=base +sugar
Page 328 Nucleoside=base +sugar

19 The Common Monosaccharides Have Cyclic Structure
Page 206 & 207 The Common Monosaccharides Have Cyclic Structure anomeric carbon 半縮醛 anomeric carbon 1

20 Page 207 & 208 anomeric carbon 半縮酮 2 anomeric carbon

21 Page 329

22 Page 329

23 Page 329 Purine nucleosides and nucleotides usually adopt the anti conformation, where the purine ring is not above the ribose, as it would be in the syn conformation. Pyrimidines are always anti, never syn, because the 2-O atom of pyrimidines sterically hinders the ring from a position above the ribose.

24 Adenosine: A Nucleoside with Physiological Activity
Page 328 Adenosine functions as an autacoid, or local hormone, and neuromodulator. Circulating in the bloodstream, it influences blood vessel dilation, smooth muscle contraction, neurotransmitter release, and fat metabolism. Adenosine is also a sleep regulator. Adenosine rises during wakefulness, promoting eventual sleepiness. Caffeine promotes wakefulness by blocking binding of adenosine to its neuronal receptors.

25 Summary-Nucleosides Page 329 The base is linked to the sugar via a glycosidic bond The carbon of the glycosidic bond is anomeric Named by adding -idine to the root name of a pyrimidine or -osine to the root name of a purine Conformation can be syn or anti Sugars make nucleosides more water-soluble than free bases

26 Nomenclature命名法 Page 329

27 What Is the Structure and Chemistry of Nucleotides?

28 Nucleotide= base + sugar + phosphate
Page 329 & 330

29 Cyclic Nucleotides Are Cyclic Phosphodiesters
Page 330

30 cGAMP, a Cyclic Dinucleotide that Triggers a Response to Infection
Page 331 Cyclic dinucleotides such as c-di-GMP have been known since 1987 and their occurrence is as second messengers. The presence of DNA in the cytosol of animal cells is an indication of an invading bacterium or virus In response, the cytosolic DNA sensor, cyclic GMP-AMP synthase, synthesizes cGAMP Rising [cGAMP] levels trigger expression of stimulator of interferon genes (STING) and an immune response An undesirable consequence of this system is that self-nucleic acid recognition (host DNA in the cytosol) may induce autoimmune diseases such as lupus erythematosus紅斑性狼瘡

31 c-di-GMP is a signal that causes bacteria to switch from free-living single cells into formation of biofilms Page 331

32 cGAMP, a Cyclic Dinucleotide that Triggers a Response to Infection
Page 331

33 Page 330 & 331 Figure Formation of ADP and ATP by the succesive addition of phosphate groups via phosphoric anhydride linkages. Shown here is ATP synthesis. Note that the reaction is a dehydration synthesis.

34 *NDPs and NTPs Are Polyprotic Acids
Page 315 *NDPs and NTPs Are Polyprotic Acids *Nucleoside 5’-Triphosphate Are Carriers of Chemical Energy

35 Nucleoside 5'-Triphosphates Are Carriers of Chemical Energy
Page 332 Nucleoside 5'-triphosphates are indispensable agents in metabolism because their phosphoric anhydride bonds are a source of chemical energy Bases serve as recognition units Cyclic nucleotides are signal molecules and regulators of cellular metabolism and reproduction ATP is central to energy metabolism GTP drives protein synthesis CTP drives lipid synthesis UTP drives carbohydrate metabolism

36 Page 333 What Are Nucleic Acids?

37 Nucleic acids: linear polymers of nucleotides
linked 3’ to 5’ by phosphodiester bridges (bond) ---DNA (deoxyribonucleic acid) ---RNA (ribonucleic acid)

38 Phosphodiester bond Page 333

39 3.d-GACG. Notation for Nucleic Acid Structure Page 334 1.GACG
2.pGpApCpG vs GpApCpGp 3.d-GACG.

40 What Are the Different Classes of Nucleic Acids?
Page 334 DNA - one type, one purpose RNA – several types, multiple purposes ribosomal RNA - the basis of structure and function of ribosomes messenger RNA - carries the message for protein synthesis transfer RNA - carries the amino acids for protein synthesis Others: Small nuclear RNA Small non-coding RNAs

41 Page 334 & 335

42 2.[A]=[T];[C]=[G];[pyrimidine]=[purine]
Page 335 & 336 1.Antiparallel 2.[A]=[T];[C]=[G];[pyrimidine]=[purine]

43 Chargaff’s Data Held the Clue to Base Pairing
Page 335 Chargaff’s Data Held the Clue to Base Pairing

44 Page 337

45 Page 337 Nucleosome: the basic unit of chromatin structure

46 Page 337 Nucleosome: the basic unit of chromatin structure

47 Page 337

48 Do the Properties of DNA Invite Practical Applications?
Page 339 The molecular recognition between DNA strands can create a molecule with mechanical properties different from single-stranded DNA DNA double helices are relatively rigid rods DNA chains have been used to construct nanomachines capable of simple movements such as rotation and pincerlike motions More elaborate DNA-based devices can act as motors walking along DNA tracks

49 DNA Tweezers – A Simple DNA Nanomachine
Page 339

50 mRNA Page 338 heterogeneous nuclear RNA=hn RNA Intron exon

51 Page 338 heterogeneous nuclear RNA=hn RNA (also called Precursor mRNA =pre-mRNA) intron: nucleotide sequence in an RNA molecule that is part of the primary transcript but not the mature, functional RNA molecule exon: nucleotide sequence in a primary RNA transcript that is preserved in the mature, functional RNA molecule

52 Prokaryotic vs Eukaryotic mRNAs Page 338
(polycistronic)operon (monocistronic) Important message : Protein this word revise to polypeptide

53 polycistronic mRNA: an mRNA molecule that
Page 338 polycistronic mRNA: an mRNA molecule that codes for more than one polypeptide monocistronic mRNA: an mRNA molecule that codes for one polypeptide

54 rRNA Page 339 & 340 S (sedimentation coefficient)=10-13 sec

55 Page 339 Sedimentation coefficients are a measure of the velocity with which a particle sediments in a centrifugal force field. Sedimentation coefficients are expressed in Svedbergs (symbolized S), named to honor The Svedberg, developer of the ultracentrifuge. One S=10-13 sec.

56 Unusual Bases in rRNA Page 340

57 tRNA Page 340 aminoacyl-tRNA synthetase codon for alanine:5’-GCC-3’
anticodon in tRNA:3’-CGG-5’

58 Transfer RNAs Carry Amino Acids to Ribosomes for Use in Protein Synthesis
Page 340 Small polynucleotide chains contain 73 to 94 residues each Several bases usually methylated Each a.a. has at least one unique tRNA which carries the a.a. to the ribosome 3'-terminal sequence is always CCA-3′-OH. The a.a. is attached in ester linkage to this 3′-OH. Aminoacyl-tRNA molecules are the substrates of protein synthesis

59 1.Small nuclear RNAs (sn RNAs)
Other RNAs Page 341 1.Small nuclear RNAs (sn RNAs) ---found in nucleus of eukaryotic cells nucleotides ---some are methylated or modified ---associate with specific proteins to form small nuclear ribonucleoprotein particles (snRNPs) in nucleus ---involve in the processing of eukaryotic gene transcripts (hn RNA) into mature messenger RNA spliceosome

60 2.Small RNAs Page 341 ---21-28 nucleotides
---also called noncoding RNAs [ or ncRNAs] ---target DNA or RNA through complementary base paring ---Small RNAs are classified into a number of subclasses (1)small interfering RNAs (si RNAs) (2)micro RNAs (miRNAs) (3)small nucleolar RNAs (snoRNAs)

61 3. Long Noncoding RNAs (lincRNAs) a class of regulatory RNAs
Page 342 3. Long Noncoding RNAs (lincRNAs) a class of regulatory RNAs are sometimes referred to as “long intergenic noncoding RNAs” or “long intervening noncoding RNAs” (lincRNAs). - RNA transcripts greater than 5 kb in size that do not code for proteins play roles in the regulation of chromatin structure and gene repression. Interestingly, some encode short

62 Page 341 knockdown vs knockout
miRNA gene is transcribed into pri-miRNA. Pri-miRNA is processed into hairpin pre-miRNA. Pre-miRNAs are transported to cytoplasm. Pre-miRNAs are processed into short, mature miRNA duplexes. Mature miRNAs complex with RISC-like structure. miRNA/RISC complex binds to target mRNA. mRNA is translationally repressed. knockdown vs knockout 62

63 Page 341 miRNA Gene Targeting

64 Page 341 Structure of siRNA

65 Page 341 RNAi Mechanism

66 Differences between DNA and RNA:
Page 342 Differences between DNA and RNA: 1.DNA contains 2-deoxyribose instead of ribose 2.DNA contains thymine instead of uracil

67 Page 343

68 Page 343

69 RNA Is Susceptible to Hydrolysis by Base, But DNA Is Not
Page 343 & 344

70 Page 343 & 344 *apurinic acid

71 The Enzymes That Hydrolyze Nucleic Acids Are Phosphodiesterases
Page 343 Phosphodiester bond Enzymes that hydrolyze nucleic acids are called nucleases 71

72 nuclease phosphodiesterase Page 345

73 Page 345

74 ---nucleases(e.g. nuclease S1)
Page 345 nuclease : ---DNases ---RNases ---nucleases(e.g. nuclease S1)

75 Page 345

76 Classification of Restriction Enzyme:
Page 345 & 347 Classification of Restriction Enzyme: 1.Type I 2.Type II 3.Type III

77 Page 347

78 Page 347

79 Page 347 44=256 46=4096 protruding ends

Download ppt "Nucleotides & Nucleic Acids"

Similar presentations

Biochemistry 2/e - Garrett & Grisham Copyright © 1999 by Harcourt Brace & Company Chapter 11 Nucleotides and Nucleic Acids to accompany Biochemistry, 2/e.

Biochemistry 2/e - Garrett & Grisham Copyright © 1999 by Harcourt Brace & Company Chapter 11 Nucleotides and Nucleic Acids to accompany Biochemistry, 2/e.
Nucleic Acids Nucleic acids are molecules that store information for cellular growth and reproduction There are two types of nucleic acids: - deoxyribonucleic.

Nucleic Acids Nucleic acids are molecules that store information for cellular growth and reproduction There are two types of nucleic acids: - deoxyribonucleic.
Chapter 19 (part 1) Nucleic Acids. Information encoded in a DNA molecule is transcribed via synthesis of an RNA molecule The sequence of the RNA molecule.

Chapter 19 (part 1) Nucleic Acids. Information encoded in a DNA molecule is transcribed via synthesis of an RNA molecule The sequence of the RNA molecule.
Nucleic Acids - RNA and DNA is a complex, high-molecular- weight biochemical macromolecule composed of chains that convey genetic information. The most.

Nucleic Acids - RNA and DNA is a complex, high-molecular- weight biochemical macromolecule composed of chains that convey genetic information. The most.
Chapter 10 Nucleotides and Nucleic Acids Biochemistry by

Chapter 10 Nucleotides and Nucleic Acids Biochemistry by
Chapter 10 Nucleotides and Nucleic Acids

Chapter 10 Nucleotides and Nucleic Acids
Biomacromolecules Pt III: Nucleic Acids. Nucleic acids Linear polymers made up of monomers called nucleotides. They are of critical importance to the.

Biomacromolecules Pt III: Nucleic Acids. Nucleic acids Linear polymers made up of monomers called nucleotides. They are of critical importance to the.
Reginald H. Garrett Charles M. Grisham Chapter 10 Nucleotides and Nucleic Acids.

Reginald H. Garrett Charles M. Grisham Chapter 10 Nucleotides and Nucleic Acids.
1 2 3 4 Review: Proteins and their function in the early stages of replication 1 = initiator proteins 2 = single strand binding proteins 3 = helicase 4.

Review: Proteins and their function in the early stages of replication 1 = initiator proteins 2 = single strand binding proteins 3 = helicase 4.
The Molecular Genetics of Gene Expression

The Molecular Genetics of Gene Expression
RNA (Ribonucleic acid)

RNA (Ribonucleic acid)
Reginald H. Garrett Charles M. Grisham www.cengage.com/chemistry/garrett Reginald Garrett & Charles Grisham University of Virginia Chapter 10 Nucleotides.

Reginald H. Garrett Charles M. Grisham Reginald Garrett & Charles Grisham University of Virginia Chapter 10 Nucleotides.
TOPICS IN (NANO) BIOTECHNOLOGY Lecture II 3 march 2004 PhD Course.

TOPICS IN (NANO) BIOTECHNOLOGY Lecture II 3 march 2004 PhD Course.
Function of RNA Since DNA cannot leave the nucleus, RNA molecules will convert the written instructions into proteins in the cytoplasm Genes are coded.

Function of RNA Since DNA cannot leave the nucleus, RNA molecules will convert the written instructions into proteins in the cytoplasm Genes are coded.
PROTEIN SYNTHESIS. Protein Synthesis: overview  DNA is the code that controls everything in your body In order for DNA to work the code that it contains.

PROTEIN SYNTHESIS. Protein Synthesis: overview  DNA is the code that controls everything in your body In order for DNA to work the code that it contains.
Transcription Packet #20 5/31/2016 2:49 AM1. Introduction  The process by which information encoded in DNA specifies the sequences of amino acids in.

Transcription Packet #20 5/31/2016 2:49 AM1. Introduction  The process by which information encoded in DNA specifies the sequences of amino acids in.
DNA Deoxyribonucleic Acid (DNA) is found in what part of the cell? Nucleus.

DNA Deoxyribonucleic Acid (DNA) is found in what part of the cell? Nucleus.
Structure and functions of RNA. RNA is single stranded, contains uracil instead of thymine and ribose instead of deoxyribose sugar. mRNA carries a copy.

Structure and functions of RNA. RNA is single stranded, contains uracil instead of thymine and ribose instead of deoxyribose sugar. mRNA carries a copy.
Introduction to Molecular Biology

Introduction to Molecular Biology
RiboNucleic Acid (RNA) -Contrast RNA and DNA. -Explain the process of transcription. - Differentiate between the 3 main types of RNA -Differentiate between.

RiboNucleic Acid (RNA) -Contrast RNA and DNA. -Explain the process of transcription. - Differentiate between the 3 main types of RNA -Differentiate between.

Similar presentations

Ads by Google