Biochemistry

1. NUCLEIC ACID
GENETIC PROTEINS
NUCLEOPROTEINS

2. • There are two types of nucleic acids, namely
• deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
• Primarily, nucleic acids serve as repositories and transmitters of genetic
information
• Brief history DNA was discovered in 1869 by Johann Friedrich Miescher, a
Swiss researcher.
• The demonstration that DNA contained genetic information was first made in
1944, by Avery, Macleod and MacCary

3. • Functions of nucleic acids :
• DNA is the chemical basis of heredity and may be regarded as the
reserve bank of genetic information.
• DNA is exclusively responsible for maintaining the identity of different
species of organisms over millions of years.
• Further, every aspect of cellular function is under the control of DNA.
• The DNA is organized into genes, the fundamental units of genetic
information.

4. •Components of nucleic acids:
• Nucleic acids are the polymers of nucleotides
(polynucleotides) held by 3c and 5c phosphate bridges.
• nucleic acids are built up by the monomeric units—
nucleotides (It may be recalled that protein is a polymer
of amino acids).

5. NUCLEIC ACIDS
• Two Types:
• DNA (Deoxy Ribonucleic Acid)
• RNA (Ribonucleic Acid)
• Polymers of nucleotides (polynucleotides) held by 3' and 5'
phosphate bridges
• Made up of monomeric units – nucleotides

6. NUCLEOTIDES
• Nucleotides are composed of a nitrogenous base, a pentose sugar and a
phosphate.
• Nucleotides perform a wide variety of functions in the living cells, besides
being the building blocks or monomeric units in the nucleic acid (DNA and
RNA) structure.
• These include their role as structural components of some coenzymes of B-
complex vitamins (e.g. FAD, NAD+), in the energy reactions of cells (ATP is
the energy currency), and in the control of metabolic reactions.

7. COMPOSITION OF NUCLEOTIDES
DNA: A,G,C,T
RNA: A,G,C,U

8. what is difference between nucleoside and
nucleotide
• STRUCTURE OF NUCLEOTIDES
Sugar
bas
e
NUCLEOSIDE
sugar
base
NUCLEOTIDE
p

9. NITROGENOUS BASES
• The nitrogenous bases found in nucleotides are aromatic
heterocyclic compounds
• Two types:
• Purine
• Pyrimidine

10. NITROGEN BASE
Purine ring
Pyrimidine ring

11. purines

12. pyrimidine

13. MAJOR PURINE BASES IN NUCLEIC ACIDS
• Consists of a pyrimidine ring & imidazole ring fused
together.
• Purines are numbered in the anti-clockwise direction

14. MAJOR PYRIMIDINE BASES IN NUCLEIC
ACIDS
• Pyrimidines are numbered in clockwise
• DNA contains - C&T
• RNA contains - C&U

15. OTHER BIOLOGICAL IMPORTANT BASES
• Xanthine, Hypoxanthine are the intermediate products in
purine degradation
• End product of purine degradation – Uric acid

16. SUGAR OF NUCLEIC ACIDS
• The 5c Monosaccharides (Aldo-pentose) are found in the
nucleic acid
• RNA -- D-Ribose
• DNA -- D-deoxyribose
•Two sugars differ in structure at C2
•Deoxyribose has one oxygen less at C2 compound to ribose

17. NUCLEOSIDE : BASE + SUGAR
• The sugar is linked to the heterocyclic base via a -N-
glycosidic bond to N-1 of a Pyrimidine or N-9 of a Purine

18. • How ribose sugar gets attached to nitrogenous base?
H2O
𝛽 − 𝑁
− 𝐺𝐿𝑌𝐶𝑂𝑆𝐼𝐷𝐼𝐶 𝐵𝑂𝑁𝐷
Adenylic acid
adenine
ribonucleotide

19. THE NAMES OF PURINE NUCLEOSIDES END
IN OSINE AND THE NAMES OF PYRIMIDINE
NUCLEOSIDES END IN -IDINE
Nitrogenous base Ribonucleoside Deoxy ribonucleoside
Adenine Adenosine (A) Deoxyadenosine (dA)
Guanine Guanosine (G) Deoxyguanosine (dG)
Thymine --- Deoxythymidine (dT)
Uracil Uridine (U) ---
Cytosine Cytidine (C) Deoxycytidine (dC)

20. NUCLEOTIDE : NUCLEOSIDE + PHOSPHATE
• Nucleosides with a phosphoryl group esterified to a hydroxyl
group of the sugar forms Mononucleotides

21. NUCLEOTIDES

22. NUCLEOTIDES
Adenosine monophosphate Adenosine triphosphate

23. Base Ribonucleotides Deoxyribonucleotide
Adenine (A) Adenosine
monophosphate(AMP)/ Adenylic
acid
2’Deoxyadenosine
monophosphate (2’ Damp), /
deoxy adenylic acid
Guanine(G) (GMP )Guanosine
monophosphate/ guanylic acid
2’Deoxyguanosine
monophosphate
(2’ dGMP) / deoxyguanylic acid
Cytosine (C ) Cytidine monophosphate (CMP)/,
cytidylic acid
2’ Deoxycytidine
monophosphate (2’dCMP), /
deoxycytidylic acid
Thymine ( T) 2’Deoxythymidine
monophosphate(2’Dtmp) ,/
deoxythymidylic acid
Uracil ( U) Uridine monophosphate

24. BIOLOGICAL IMPORTANT
NUCLEOTIDES & NUCLEOSIDES

25. BIOLOGICAL IMPORTANT NUCLEOTIDES &
NUCLEOSIDES
• Classification:
• Adenosine nucleotides : ATP, ADP, AMP & c AMP
• Guanosine nucleotides : GTP, GDP, GMP & c GMP
• Uridine nucleotides : UTP, UDP, UMP &
UDP - Glucose
• Cytidine nucleotides : CTP, CDP, CMP & Deoxy
CDP
(derivatives of glucose
,choline)

26. ADENOSINE NUCLEOTIDES
• Adenosine Mono Phosphate (AMP)
• Component of many coenzymes such as NAD+, NADP+,
FAD, Coenzyme A
• Coenzymes are essential for the metabolism of
carbohydrate, lipid and protein
• Adenosine Di Phosphate (ADP)
• Controls cellular respiration
• Muscle contraction

27. ADENOSINE NUCLEOTIDES
• Adenosine Tri Phosphate (ATP)
• Storage battery of the tissues
• Required as a source of energy in fatty acid synthesis,
gluconeogenesis, cholesterol synthesis, protein
synthesis
• Muscle contraction, nerve transmission

28. CYCLIC AMP (C-AMP)
• Formed from ATP by the action of adenylate cyclase
• Acts as a second messenger for many hormones e.g.
epinephrine, glucagon
• Enhances the degradation of storage fuels like fat and
glycogen by stimulating lipolysis, glycogenolysis
• Inhibits the aggregation of blood platelets
• Increases the secretion of acid by the gastric mucosa

29. CYCLIC AMP

30. GUANOSINE NUCLEOTIDES
• Oxidation of Succinyl CoA to Succinate in the TCA cycle
involves phosphorylation of Guanosine Di Phosphate (GDP)
to form GTP
• Guanosine Tri Phosphate (GTP)
• Stimulation of adenylate cyclase enzyme
• Protein Synthesis

31. GUANOSINE NUCLEOTIDES
• Cyclic Guanosine 3’5’-Monophosphate (c-GMP)
• formed from GTP by guanylyl cyclase
• intracellular signal or second messenger that can act
antagonistically to c-AMP
• involved in smooth muscle relaxation and vasodilation

32. URIDINE NUCLEOTIDES
• Uridine Di Phosphate (UDP)
• Involved in glycogenesis
• UDP- glucose and UDP- galactose takes part in
galactose metabolism and synthesis of lactose and
cerebrosides
• UDP- glucuronic acid is required for detoxification and for
synthesis of mucopolysaccharides

33. CYTIDINE NUCLEOTIDES
• CTP & CDP are involved in the formation of phospholipids
• CDP- choline is involved in the synthesis of sphingomyelin

34. MISCELLANEOUS
PAPS( Phospho Adenosine Phospho Sulphate):
• Formed from ATP & SO4 in liver
• Required for
• Biosynthesis of mucopolysaccharides
• Formation of Sulpholipids
• Conjugation of phenols, indole, ethereal SO4

35. SYNTHETIC NUCLEOTIDE ANALOGS
(OR)
ANTI-METABOLITES

36. INTRODUCTION
• Chemically synthesized analogues of Purines, Pyrimidines
their nucleosides, and nucleotides have therapeutic
applications in clinical medicine
• analogues Prepared either by altering the heterocyclic ring
or sugar moiety
• Inhibits of specific enzymes essential for nucleic acid
synthesis by the drug.
• Used chemotherapeutically to control cancer or infections

37. ANTI-METABOLITES
CYTARABINE
• Chemotherapy of cancer & viral infection
AZATHIOPURINE
• Immuno-Suppressive Agent (ISA)
• Used during organ transplantation

38. ANTI-METABOLITES
AZIDOTHYMIDINE (AZT)
• Structural analogue of Thymidine, used in the treatment
of AIDS
• Terminates DNA synthesis catalyzed by the reverse
transcriptase of retroviruses such as HIV
5-Iododeoxyuridine
• Used in the treatment of herpetic keratitis (Infection of
the cornea by herpers virus)

39. ANTI-METABOLITES
Arabinosyl adenine
• Treatment of neurological disease, viral encephalitis
Allopurinol
• Treatment of hyperuricaemia and Gout

40. PLANTS CONTAINING METHYLATED
PURINES
Caffeine (1,3,7-tri methyl xanthine)
• Acts as a CNS stimulant, restores alertness reduces drowsiness
• Excess intake of caffeine causes
• Tachycardia (Increases heart rate)
• Increases the force & depth of respiration

41. PLANTS CONTAINING METHYLATED
PURINES
Theobromine (3,7-Di methyl xanthine)
• Found in leaves of the tea leaves and chocolate
• Vasodilator, reduces blood pressure
• Increases heart rate & increases frequency of micturition
Theophylline (1,3-Di methyl xanthine)
• Relaxes bronchial smooth muscle
• Increases heart rate, blood pressure & renal blood flow
• Stimulates the CNS
• Inhibits tubular reabsorption of Na+ & Cl-

42. OVERALL FUNCTIONS OF NUCLEOTIDES
• Building blocks or monomeric units of nucleic acid (DNA and RNA)
• Involved in the energy reactions of cell e.g. ATP
• Controls metabolic reactions
• Cyclic AMP and Cyclic GMP act as second messengers
• Carries of high energy intermediates in carbohydrate, lipid and protein
metabolism

43. THANK YOU