purine and pyrimidine

1. DEPARTMENT OF BIOTECHNOLOGY &
MICROBIOLOGY
SUBJECT- BIOMOLECULES (Paper 2)
GUIDED BY :-
MR. ARPAN DEY
PRESENTED BY:-
ANKIT SHARMA
M.Sc 1st sem

3.  Introduction
 History
 Nitrogenous base
 Composition
 Deoxyribonucleic acid (DNA)
 Ribonucleic acid (RNA)
 Mechanism of action
 Function
 Conclusion
 Current research
 Reference

4.  Purine and Pyrimidine are the names of the
parent compounds of two types of nitrogen
containing heterocyclic aromatic compound.
 Adenine and guanine are the principle Purine of
both DNA and RNA.
 Pyrimidine that occur in DNA are cytosine and
thymine. Cytosine and uracil are the Pyrimidine
in RNA.

5.  The word Purine was coined by the German
chemist Emil Fischer in 1884. He synthesized
it for the first time in 1898. The starting
material for the reaction sequence was uric
acid.
 The origin of the term Pyrimidine dates back
to 1884 when Pinner coined the term from a
combination of the words pyridine and
amidine because of the structural similarity
to those compound.

6.  Two long strands makes the shape of a
double helix.
 Two strands run in opposite directions to
each other and are therefore anti-parallel.
 Chemically, DNA consists of two long
polymers of simple units called nucleotides,
with backbones made of base, sugars and
phosphate groups.

7.  Types:- Purine - (adenine and guanine)
Pyrimidine –(cytosine & thymine)
 Purines - Adenine and Guanine (fused
five- and six- membered heterocyclic
compounds)
 Pyrimidines – Cytosine Thymine & Uracil
(six- membered rings) Uracil (U) - Usually
takes the place of thymine in RNA.
 PAIRING : A =T and A=U and G≡C

8.  Purine bases include adenine (6-
aminopurine) and guanine (2-amino-6-
oxypurine).

9.  The pyrimidine bases are thymine (5-
methyl-2,4-dioxipyrimidine), cytosine (2-oxo-
4-aminopyrimidine), and uracil (2,4-
dioxoypyrimidine)

10.  Nucleotide hydrolysis produces two types of
substances derived from the heterocyclic
rings purine and pyrimidine known as the
purine and pyrimidine bases.

11.  DNA is a nucleic acid that contains the genetic
instructions used in the development and
functioning of all known living organisms and
some viruses.
 The DNA molecule consists of two strands that
wind around one another to form a shape known
as a double helix.
 Each strand has a backbone made of alternating
sugar (deoxyribose) and phosphate groups.
Attached to each sugar is one of four bases--
adenine (A), cytosine (C), guanine (G), and
thymine (T).
 The two strands are held together by bonds
between the bases; adenine bonds with thymine,
and cytosine bonds with guanine.

13.  A nucleic acid that carries the genetic message
from DNA to ribosomes and is involved in the
process of protein synthesis is referred to as
RNA(Ribose Nucleic Acid).
 Ribonucleic acid is one of the two types of nucleic
acids found in all cells.
 RNA is similar to DNA but containing ribose in place
of deoxyribose and uracil in place of thymine.
 RNA is a nucleic acid polymer consisting of
nucleotide monomers that acts as a messenger
between DNA and ribosomes and is also responsible
for making proteins out of amino acids. Some
viruses use RNA instead of DNA as their genetic
material.

15. The basic mechanism of action of
purine and pyrimidine
antimetabolites is similar.
 These compounds diffuse into cells
(usually with the aid of a membrane
transporter1) and are converted to
analogues of cellular nucleotides by
enzymes of the purine or pyrimidine
metabolic pathway.

16.  Purine Catabolism :
The end product of purine catabolism in man
is uric acid. Uric acid is formed primarily in
the liver and excreted by the kidney into the
urine.

17.  Pyrimidine Catabolism : In contrast to
purines, pyrimidines undergo ring cleavage
and the usual end products of catabolism are
beta-amino acids plus ammonia and carbon
dioxide.

18.  DNA is very important for life. It can
replicate well, which means that the next
generation will retain the characteristics of
the parents.
 DNA, adenine bonds to thymine via two
hydrogen bonds, while guanine bonds to
cytosine via three hydrogen bonds. In all
DNA, the amount of adenine should equal the
amount of thymine, and the amount of
guanine should equal the amount of cytosine
(1:1 ratio of A:T and G:C).

19.  Electrochemical evaluation of DNA methylation
level based on the stoichiometric relationship
between purine and pyrimidine basesPo Wang 1 ,
Hanbin Chen, Jiuying Tian, Zong Dai, Xiaoyong
ZouAffiliations expandPMID: 23454340 DOI:
10.1016/j.bios.2013.01.057.
 Accurate Base Pair Energies of Artificially
Expanded Genetic Information Systems (AEGIS):
Clues for Their Mutagenic CharacteristicsB Behera
1 , P Das 1 , N R Jena 1Affiliations expandPMID:
31290661 DOI:
10.1021/acs.jpcb.9b04653.23/07/2019.

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Himalaya Publishing House. Gerald Karp - Cell and
Molecular biology, 4th Edition (2005).
 P.K. Gupta- Cell and molecular biology, Second
Edition (2003), Rastogi publications.
 Tortora, Funke and Case-Microbiology : An
introduction 6th Edition (1998), Binjamin/
Cummings Publishing Co.
 K. Wilson and J. Walker :Principle and Techniques
of Biotechnology and Molecular Biotechnology.