1. Introduction to Nucleic Acids
Lecture # 1
Dr. Shumaila Asim

2. Learning Outcomes Knowledge; Define and explain nucleic acids
Describe the types of nucleic acids
Content
Nucleic Acids
Types Of Nucleic Acids

3. Nucleic acids
Nucleic acids are the most important biological macromolecules found in abundance in all living things
They are involved in encoding, transmitting and expressing genetic information
Or we can say that information is conveyed through the nucleic acid sequence.

4. Brief history
1869: isolated DNA from salmon sperm (Friedrich Miescher)
1944: proved DNA is genetic materials (Avery et al.)
1953: discovered DNA double helix (Watson and Crick)
1968: decoded the genetic codes (Nirenberg)
1981: invented DNA sequencing method (Gilbert and Sanger)
1987: launched the human genome project
2001: accomplished the draft map of human genome

5. Deoxyribonucleic acid, DNA
Ribonucleic acid, RNA

6. The distribution of nucleic acids in the eukaryotic cell
DNA is found in the nucleus
with small amounts in mitochondria and chloroplasts
RNA is found throughout the cell

7. NUCLEIC ACID STRUCTURE
Nucleic acids are polynucleotides
Their building blocks are nucleotides

8. phosphate
nucleic acid
pentose
nucleotides
nucleosides
bases

9. NUCLEOTIDE STRUCTURE NUCLEOTIDE BASE PURINES PYRIMIDINES Adenine (A)
PHOSPATE
SUGAR
Ribose or Deoxyribose
BASE
PURINES
PYRIMIDINES
Adenine (A)
Guanine(G)
Cytocine (C)
Thymine (T)
Uracil (U)
NUCLEOTIDE

10. Ribose is a pentose C1 C5 C4 C3 C2 O

11. RIBOSE
DEOXYRIBOSE
CH2OH H OH C O

12. BASES Two types of bases:
1. Purines are fused five- and six-membered rings
Adenine A DNA RNA
Guanine G DNA RNA
2. Pyrimidines are six-membered rings
Cytosine C DNA RNA
Thymine T DNA
Uracil U RNA

13. Nucleic Acid Bases
Pyrimidines
Purines

14. Phosphate Groups Mono-, di- or triphosphates
Phosphates can be bonded to either C3 or C5 atoms of the sugar

17. Nucleosides
Result from linking one of the sugars with a purine or pyrimidine base through an N-glycosidic linkage
Purines bond to the C1’ carbon of the sugar at their N9 atoms
Pyrimidines bond to the C1’ carbon of the sugar at their N1 atoms

18. Nucleosides

20. Nucleosides in DNA Base Sugar Nucleoside
Adenine (A) Deoxyribose Adenosine
Guanine (G) Deoxyribose Guanosine
Cytosine (C) Deoxyribose Cytidine
Thymine (T) Deoxyribose Thymidine

21. Nucleosides in RNA Base Sugar Nucleoside Adenine (A) ribose Adenosine
Guanine (G) ribose Guanosine
Cytosine (C) ribose Cytidine
Uracil (U) ribose Uridine

22. Nucleotides
Result from linking one or more phosphates with a nucleoside onto the 5’ end of the molecule through esterification

23. Nucleotides in DNA and RNA
dAMP Deoxyadenosine monophosphate
dGMP Deoxyguanosine monophosphate
dCMP Deoxycytidine monophosphate
dTMP Deoxythymidine monophosphate
RNA
AMP adenosine monophosphate
GMP guanosine monophosphate
CMP cytidine monophosphate
UMP uridine monophosphate

24. Naming Conventions Nucleosides: Nucleotides:
Purine nucleosides end in “-sine”
Adenosine, Guanosine
Pyrimidine nucleosides end in “-dine”
Thymidine, Cytidine, Uridine
Nucleotides:
Start with the nucleoside name from above and add “mono-”, “di-”, or “triphosphate”
Adenosine Monophosphate, Cytidine Triphosphate, Deoxythymidine Diphosphate

25. THE SUGAR-PHOSPHATE BACKBONE
The nucleotides are all orientated in the same direction
The phosphate group joins the 3rd Carbon of one sugar to the 5th Carbon of the next in line.

26. The bases are attached to the 1st CarbonP G C A T
ADDING IN THE BASES
The bases are attached to the 1st Carbon
Their order is important It determines the genetic information of the molecule

27. Functions of Nucleic Acids
Direction of Metabolism
Synthesis of Proteins
Control of synthesis of Enzymes
Transfer of Genetic information
Essential substance of genes
Causation of cancers (malignancies)