Bacterial genetics is the study of how genetic information is transferred, either from a particular bacterium to its offspring or between interbreeding lines of bacteria, how genetic information is expressed, and how the genetic information (genotype) determines the physiology of the bacterium (phenotype).

2. Saleh Bahaj
Prof. of Medical
Microbiology/Immunology
Bacterial genetics
(Bacterial chromosome)
Lecture 10

3. Bacterial genetics
I) Bacterial chromosome
II) Plasmid
III) Transposable genetic elements
IV) Bacterial variation

4. Objectives
By the end of this lecture the students will be able
to:-
III) Function
Bacterial chromosome
I) Definitions
II) Composition

5. Bacterial genetics
I) Definitions
1) Genetics

6. 1) Genetics
Science that
defines and
analyzes heredity

7. Bacterial genetics
I) Definitions
2) Bacterial genome

8. 2) Bacterial genome
All genes in bacterial cell

9. Bacterial genetics
I) Definitions
3) Gene

10. 3) Gene
 A segment of
DNA that code
for specific
character
Unit of inheritance

11. Bacterial genetics
I) Definitions
3) Genome & Gene

12. 3) Genome & Gene
gene
Genome

13. Bacterial genome
All genes in bacterial cell
I) Chromosome
Bacterial genome may:-
Bacterial
chromosome
II) Plasmid
IV) Prophage
III) Transposable genetic elements
(Essential)

14. Bacterial genetics
I) Definitions
 Bacterial chromosome

15.  Bacterial chromosome (Nucleoid)
(Supercoiled)
 Single chromosome
 dsDNA
Circular
1mm length
4000 – 5000 kbp
 Prokaryotic

16.  Bacterial chromosome
Base pair
A T
C G
(4000kbp)
4000x1000 =
4,000,000 bp
Complementary
Base pair

17. Bacterial chromosome
Bacterial genome
II) Composition

18. II) Composition of chromosome
 Double helix DNA
 Sugar - Nitrogenous base
(ATCG)
 Two strand of nucleotides
P S
P
S
S
P
P
S
 Phosphate-sugar backbone
P
S
S
S
S
P
P
P

19. II) Composition of chromosome
 Two strands
are held together by
hydrogen bonds
between
complementary
bases

20. II) Composition of chromosome
Complementary bases
A T C A G T G C
T A G T C A C G

21. III) Function
Bacterial genome
(B. Chromosome)

22. III) Function of Bacterial chromosome
DNA
RNA
Protein
1- Replication
A) Transcription
B) Translation
2) Gene
expression

23. 1) Replication (Semi-conservative)
DNA
polymerase
New bases

24. 2) Gene expression
A) Transcription
B) Translation

25. A) Transcription
 Formation of
mRNA from
DNA
RNA polymerase

26. A) Transcription
Sigma factor

27. A) Transcription
Codon=3 nucleotides
on mRNA

28. B) Translation
m
The synthesis of
a protein from a
mRNA template
By ribosome.

29. B) Translation
mRNA
Ribosome
tRNA
AUG CGC
Codon mRNA

30. B) Translation
 tRNA
A U G CGC
Codon1 Codon2
mRNA
Anti-codon
Amino acid
 Carry specific amino
acid with anti-codon
Codon1= N-formylmethionine

31. B) Translation
mRNA
Ribosome
tRNA
AUG CGC
Codon mRNA

32. B) Translation
Peptidyl
transferase

33. B) Translation
70S ribosome moves a distance
of one codon down the mRNA
Peptidyl transferase &Translocation

34. B) Translation
 Peptidyl transferase
 Translocation

35. Objectives
By the end of this lecture the students will be able
to:-
III) Function
Bacterial chromosome
I) Definitions
II) Composition