DOGMA SENTRAL BIOLOGI

Matakuliah Genetika
Jurusan Biologi
Fakultas Matematika dan Ilmu Pengetahuan Alam
Universitas Lampung
References
and the story goes...
Outline
• Genetic material
• DNA as genetic material
• DNA and RNA
Biomolecules
DNA in a chromosome
Genetic material
For a molecule to serve as the genetic material,
it must exhibit four crucial characteristics:
• Replication
• Storage of information
• Expression of information
• Source of variability
DNA as genetic material
• Fred Griffith (1928)
• Avery, MacLeod, and McCarty (1944)
• Alfred Hershey dan Martha Chase (1952)
DNA as genetic material
Fred Griffith (1928)
DNA as genetic material
Fred Griffith (1928)
DNA as genetic material
Avery, MacLeod, and McCarty (1944)
DNA as genetic material
Avery, MacLeod, and McCarty (1944)
DNA as genetic material
Alfred Hershey dan Martha Chase (1952)
DNA as genetic material
Alfred Hershey dan Martha Chase (1952)
DNA Structure
DNA Structure
• A research group at King's College in London, led by
Maurice Wilkins and Rosalind Franklin, also was
studying the structure of DNA by using X-ray
diffraction and obtained strikingly better pictures of
the molecule
DNA Structure
•
X-ray diffraction photograph by Rosalind Franklin using the B form of
purified DNA fibers. The strong arcs on the periphery represent closely
spaced aspects of the molecule, allowing scientists to estimate the
periodicity of the nitrogenous bases, which are 3.4 Å apart. The inner
cross pattern of spots reveals the grosser aspects of the molecule,
indicating its helical nature.
DNA Structure
Watson and Crick
investigated the
structure of DNA, not
by collecting new data
but by using all
available information
about the chemistry of
DNA to construct
molecular models
DNA Structure
DNA Structure
DNA Structure
DNA Structure
Acid
Base
5’
1’
4’
Monophosphate
Diphosphate
Triphosphate
Sugar
3’
2’
Ribose,
Deoxyribose
Adenine
Guanine Purine
Thymine
Cytosine Pyrimidine
Uracil
Chargaff’s rule
In a DNA double helix:
Adenine = Thymine
Guanine = Cytosine
So,
Adenine + Guanine = Thymine + Cytosine
Purine = Pyrimidine
Aturan Chargaff
• Diketahui bahwa kandungan Adenin dari
molekul DNA suatu makhluk hidup adalah
20%, tentukan kandungan Guanin, Timin dan
Sitosin pada molekul DNA tersebut!
A = 20%
A = T = 20%
G + S = 100% – (20%+20%)
G + S = 60%
G = S = 30%
DNA in a cell
• Chromosomal DNA
• Extrachromosomal DNA
DNA & RNA
• Struktur
– Gula Pentosa
– Basa Nitrogen
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Jenis rantai
Panjang rantai
Lokasi
Fungsi/Peran
Gula Pentosa
Basa Nitrogen
Rantai
Peran