2. DNA
MoLECULE of HEREDITY
 DNA/RNA structures
 GENETIC code
 Transcription

3. DNA
Overview:
Background/history
DNA structure
Genetic information in eukaryotic

4. A Short History
1869 - Miescher isolated DNA the first time
1953 - Watson and Crick proposed the double helix as
the structure of DNA
1957 - Kornberg discovered DNA polymerase
1961 - Marmer and Doty discovered DNA renaturation
1962 - Arber, Nathans and Smith discovered restriction
endonucleases
1966 - Nirenberg, Ochoa, and Khorana figured out the
genetic code

5. What is DNA?
• DNA (deoxyribonucleic acid) is
a double helix: two strands of
genetic material spiraled around
each other.
• Everyone’s chemical structure
of DNA is the same, the only
difference is in the ordering of
base pairs.

6. BUILDING BLOCK of DNA
 Nucleotides
consist of a sugar,
phosphate and
nitrogenous base

7. Nitrogenous base of DNA
Purine nucleotides
• A - Adenine
• G - Guanine
Pyrimidine
nucleotides
• T - Thymine
• C - Cytosine

8. Chemical composistion of
DNA

10. DNA strand extend from 5’ to 3’
 The DNA back-
bone was
connected by
phosphodiester
bond
Strand of DNA A-A-C-T-G-A-T-A-G-G-T-C-T-A-G
T-T-G-A-C-T-A-T-C-C-A-G-A-T-C

13. POLYNUCLEOTIDE FORMATION

16. DNA structure Watson-Crick
double helix
 The two helical polynucleotide chain coil around the
common axis. The chains are antiparalel in polarity
 Purine and pyrimidine bases are inside the helix,
whereas the phosphate and deoxyribose units are
on the outside.

18. DNA base composition is governed
by Chargaff’s Rule
 DNA has equal number of A and T residue
(A-T) and equal number of G and C residue
(G-C)
 DNA base composition range from 25-75%
G+C content.

19. RNA (ribonucleic acid)
 Component = DNA
except for
nitrogenous base is
replaced by Uracyl

20. RNA STRUCTURE

21. rRNA

22. From DNA to chromosome

23.  Humans have 23
pairs of
chromosomes.
 A part of
chromosome that
dictates a particular
trait is called a
gene.

25. Chromatin
 DNA dalam nukleus mengkombinasi dg protein
(histones)  chromatin.
 Euchromatin:
 Active in genetic transcription.
 Heterochromatin:
 Contains genes that are permanently inactivated.

27. GENE ORGANISATION
Operon:
 Is a unit of gene expression and regulation
including structural genes and control
elements in DNA recognised by regulator
gene product/s.

28. Gene organization

29. Gene structure in eukaryote

31. REGULATORy element
 Promoter
region where RNA polymerase bind.
 Sigma factor : to ensure that the bacterial RNA polymerase
binds in a stable manner to DNA only at promotors, not
other site

32.  Operator
DNA region where repressor protein binds and start to
inhibit tanscription .

33.  Enhancers
 Element regulator positif.
 Repressor
 Menghambat transcripsi
 Silencer
 Eleman DNA yang berinteraksi dengan repressors untuk
menghambat transcripsi.

34. Dogma of molecular biology
genome < transcriptome <
proteome
1 gene  10 or more proteins

35. DNA Replication
Components of
Replication process:
 helicase
 DNA ligase
 DNA polymerase
 topoisomerase
 VIDeO DNA rep

36. REPLIKASI DNA
Pada proses replikasi kromosom asam deoksiribonukeat, sebagai
akibatnya, menjadi sepasang cetakan, dimana setiap pola
cetakan merupakan komponen cetakan yang lain. Kita
membayangkan bahwa sebelum terjadi duplikasi ikatan-ikatan
hidrogen akan putus, dan dan kedua rantainya membuka dan
terpisah. Setiap rantai kemudian berfungsi menjadi cetakan untuk
pembentukan rantai pasangan yang baru, akhirnya kita akan
mendapatkan dua pasang rantai,dimana kita hanya punya satu
sebelumnya. Lebih jauh lagi, urutan dari pasangan-pasangan basa
tersebut akan terduplikasi sama persis.
Crick, F.H.C., and J.D. Watson, The Complementary Structure of Deoxyribonucleic Acid,
Proc.Roy.Soc.(A) 223 (1954), page 80.

38. Function of replication
enzymes
 DNA ligase: connect between nucleotide on the
lagging strand
 Topoisomerase: ….
 DNA polimerase:….

39.  DNA primase : A
enzym khusus utk
polimerisasi
nucleotide-primer
RNA pd lagging strand