This document provides information about DNA and nucleic acids. It defines DNA as deoxyribose nucleic acid and notes its location in the nucleus and mitochondria of cells. It describes DNA as being tightly packaged into chromosomes within the nucleus. It also outlines the basic components of nucleic acids, including sugars, phosphates, and nitrogenous bases, and describes how nucleotides are formed from nucleosides through phosphodiester linkages to form nucleic acid polymers. Finally, it compares the A, B, and Z forms of DNA based on parameters like helix sense, base pairs per turn, and diameter.

1. Presented by
Dr. Mrs. A. P. Kopulwar
Basics of
Molecularbiology

2. NucleicAcid

3. What Does DNA Stand For
Deoxyribose Nucleic Acid

4. Where this DNA located ?
1) Nucleus of
the Cell
2) Mitochondria
of the cell
3) Chloroplast
of plant cell

5. DNA is Tightly
Packaged into
Chromosomes
Which Reside
in the Nucleus

6. Attribute to the scientists for
their pioneer work in the field of
molecular biology…….

7. Sugar unit phosphate unit Bases
Adenine Thymine
Guanine Cytosine

10. Different bases in RNA and DNA
RNA
only
DNA
only DNA and RNA

11. Base（purine, pyrimdine) + Ribose（deoxyribos)
N-glycosyl linkage
Nucleoside+phosphate
phosphodiester linkage
Nucleotide
phosphodiester linkage
Nucleic acid

13. The building block molecule of
nucleic acid are nucleotide
In RNA: AMP,CMP,GMP,TMP
In DNA: dAMP,dCMP,dGMP,dUMP

15. The linkage in between –sugar-nitrogen base-
phosphorous ion- phosphodiester bridge
3’terminal
5’terminal
Nucleotide
residues

18. Antiparallel strand of the DNA

21. Parameter A-DNA B-DNA Z-DNA
Helix sense Right Right Left
Base pairs per turn 11 10 12
Axial rise (nm) 0.26 0.34 0.45
Helix pitch (°) 28 34 45
Base pair tilt (°) 20 –6 7
Twist angle (°) 33 36 –30
Diameter of helix
Comparison between A,B and Z form of DNA

22. RNA chain is made single stranded!
Chain is directional. Convention: 5’ 3’.
Chemical schematic One-letter code
ssDNA can
signal DNA
damage and
promote cell
death
dsRNA can
block protein
synthesis and
signal viral
infections