Download Discovery of DNA structure

Discovery of DNA
structure
DNA discovery
When protein was discovered with respect
to DNA?
Rosalind Franklin (1920-1958)
Rosalind Franklin (1920-1958)
Deoxyribonucleic Acid (DNA)
Double-stranded
helical molecule
found in the nucleus
of the cell
Replicates itself before
the cell divides,
ensuring genetic
continuity
Provides instructions
for protein synthesis
DNA structure
In Prokaryotes
In eukaryotes
DNA in prokaryotes
e.g. Bacteria
Is called nucleoid
DNA is very long can reach up to 710 meters in eukaryotes
How DNA is packed inside a small
microscopic cells?
DNA forms
Human DNA
Stores genetic
information
Genes
Movie about DNA packaging
Chemical structure of DNA
Composed of carbon, oxygen, hydrogen,
nitrogen, and phosphorus
DNA is a polymer
its structural unit is the nucleotide
composed of nitrogenous base
a pentose sugar,
a phosphate group
Chemical structure of DNA
Nitrogenous bases
Chemical structure of DNA
Chemical structure of DNA
Reading the DNA molecule is from the 5` to 3`
Base pairing of DNA
Chargaff's rules:
• The amount of adenine equals that of
thymine: [A] = [T].
• The amount of guanine equals that of
cytosine:[G] = [C]
[A] + [G] = [T]+ [C]
The amount of purine base equals that of
pyrimidine bases:
True or false
The amount of purine base equals that of
pyrimidine bases in any DNA molecules
Discovery of the central
dogma?
DNA replication
Starts at replication origin
Initiation: replication fork ( unwinding the
Double helix)
Major differences between prokaryotes and
eukaryotes
DNA replication exercise
http://www.wiley.com/college/pratt/04713938
78/student/animations/dna_replication/ind
ex.html
Enzymes involved in the replication
process
Helicase
Polymerase
Topoisomerase
SSB proteins
Ligase