all about biochemistry

1. Composition and significance
of nucleic acids

2. Composition of nucleic acids
• Nucleic acids are linear polymers(chains) of
nucleotides.
• Each nucleotide consists of three
components:
a) A purine or pyrimidine
nucleobase(sometimes termed
nitrogenous base or simply base)
b) A pentose sugar
c) And A phosphate group

3. Composition of nucleic acids
• A substructure of nucleotides formed of a nucleobase plus sugar is
termed as nucleoside.
• In their nucleotides DNA contains 2’-deeoxyrribose while RNA
contains ribose.
• Here only the difference is of the presence off a hydroxyl group.
• The nucleobases found in two nucleic acid types are different :
adenine, cytosine, and guanine are found in both DNA and RNA.
• Thymine occurs in DNA and uracil occurs in RNA.
• Phosphoric acid when attaches to a nucleoside forms nucleotide.

4. •Nucleoside
•Nucleotides

5. a) Pentose sugar
b) Nitrogenous base
1. Purines
2. Pyrimidines

6. c) Phosphate group
d) Sugar phosphate backbone

7. • Extra stability of nitrogenous bases due to tautomerism
• Examples of tautomeric forms

8. Nucleotide structure
PHOSPHATE SUGAR
Ribose or
Deoxyribose
NUCLEOTIDE
BASE
PURINES PYRIMIDINES
Adenine (A)
Guanine(G)
Cytocine (C)
Thymine (T)
Uracil (U)
© 2016 Paul Billiet ODWS

9. Significance of nucleic acids
• The storage and transmission of genetic information
• Source of information for synthesis of all proteins
• In cell division DNA serves as a source of information inherited by
progeny cells.

10. Nucleotides can also function as a carrier of chemical energy
for example :

11. Any Question ?