2. DNA, or deoxyribonucleic acid, is the
hereditary material in humans and almost all
other organisms.
Every cell in a person’s body has the same
DNA.
Most DNA is located in the cell nucleus (where
it is called nuclear DNA), cells can use.
3. cont…
but a small amount of DNA can also be found in
the mitochondria (where it is called Mitochondrial
DNA or mtDNA). Mitochondria are structures
within cells that convert the energy from food into
a form that cell can use
5. Cont…
Structure of DNA, in which two strands are wrap
around each other to form double helix
DNA is composed of base,sugar,phosphate
group
DNA bases are Adenine ,cytosine ,guanine , and
thymine
6. Cont….
The bases with Two rings are A and G are Purine
Those with only One ring T and C are Pyrimidine
A third pyrimidine, Uracil replaces Thymine in RNA
Adenine pair only with Thymine
G pair only C
7. Cont…
Phosphodiester bonds join each deoxynuclotide
link in the DNA chain
The phosphate attached to the last 5 carbon of
deoxyribose sugar of one nuclotide is attached to
the third 3 carbon of the sugar of the next
nuclotide thus forming one strand of nuclotides
connected 5 to 3 3 to 5
9. Cont…
Each base is also attached to a sugar molecule
and a phosphate molecule.
Together, a base, sugar, and phosphate are
called a nucleotide.
Nucleotides are arranged in two long strands
that form a spiral called a double helix.
The structure of the double helix is somewhat like
a ladder,
.
10. Adenine and thymine are connected
by two hydrogen bonds, and cytosine
and guanine are connected by three
hydrogen bonds.
•The pitch of helix is 3.4nm
•
11. DNA Structure
In 1953, Watson and crick postulated a three
dimensional Model of DNA Structure
It consist of two helical polynuclotide chains
Two polynucleotide chain coil around the
same axis to form a right-handed double helix
Both chains are antiparralel
Human contains about 3 billion bases and
20,000 genes on 23 pair of chromosomes
12. Discovery DNA
Mendal Discover genes pass from one parant to
another
The biochemist Fredrich Miescher isolated nuclein
from the nuclei of pus cells due to having acidic
properties it name nuclic acid
Watson and crick determined the structure of DNA
It is composed of subunits called nucleotides
Chargaff discover base pairing rules bases are
complementary
13. Function Of DNA
Carry Genetic material
DNA contain the instructions needed for an
organism to develop, survive, and reproduce
Transfer Genetic information
Control the all metabolic Reactions
