Dna and rna structure

1. Prepared by:-
TAZEEN ANWAAR
UZMA IMTIYAZ

2. INDEX
Introduction to DNA
DNA structure
Introduction to RNA
RNA Structure
Difference in DNA and RNA

3.  DNA is a polymer made of nucleotides.
 DNA is found in chromosomes , mitochondria and
chloroplast.
 DNA carries genetic information.
What is DNA?

4.  James Watson and Francis Crick worked out the three-
dimensional structure of DNA, based on work by
Rosalind Franklin
Figure 10.3A, B

5. Components of DNA
 DNA is polymer of nucleotides where each nucleotide
comprises of the following:
 Sugar molecule
 Phosphate
 Nitrogeneous bases which are pyrimidines and
purines.

7.  Each nucleotide is joined to one another in a chain by
covalent bond between the sugar of one nucleotide
and the phosphate of the next resulting in an
alternating sugar phosphate backbone.
 Hydrogen bonds bind the nitrogeneous bases of two
separate polynucleotide strands to make duble
stranded DNA.

8.  Two strands of DNA run in opposite direction thus are
anti parallel.
 Two biopolymer strands are coiled around each other
to form a double helix.

16. RNA
 RNA is a polymer of ribonucleotides linked together
by 3’ to 5’ phosphodiester linkage.

18. Types of RNA molecules:
 In all prokaryotic and eukaryotic organisms three main
classes of RNA molecules exist
1. Messenger RNA (m RNA)
2. Transfer RNA (t RNA)
3. Ribosomal RNA(r RNA)

19.  Structurally ,DNA and RNA are nearly identical
.However there are three fundametal differences that
account for the very different functions of two
molecules.

20. 1. RNA has a ribose sugar molecule while DNA has a
deoxyribose sugar.
2. RNA nucleotides have URACIL base instead of
THYMINE present in DNA.
3. RNA is a single strand structure while DNA is a
double strand structure.