al-salam alykom .. this lecture starts with basic definitions in genetic , also talk about DNA & RNA ( structures , types , similarities and differences ) . it talks about bacterial DNA ( chromosome structure / plamids structure and functions / transponon types ) later , discusses about central dogma / gene expression starting from genetic code/codons , then DNA replication , trancription and finally translation prepared by Sumia Abdalsalam Alfitoury / Libya

1. BACTERIAL GENETICS
‫للطالبة‬:‫رمضان‬ ‫السالم‬ ‫عبد‬ ‫سمية‬
‫الفيتوري‬
‫االكاديمية‬ ‫السنة‬2018/2019
‫الليبية‬ ‫االكاديمية‬/‫فرع‬‫مصراتة‬–‫ليبيا‬

2. OBJECTIVE
• Bacterial Genetics & Definitions
• Genetic Information In Bacteria
• Nucleic Acids ( DNA/RNA / Central dogma )
structures & differences
• DNA in bacteria ( chromosomes / plasimds /
transposons )
• Genetic Codon
• Prokaryotic DNA Replication
• DNA Transcription
• Protein synthesis (translation )

3. Bacterial Genetics
• Genetics is the study of heredity and
variation.
• The unit of heredity is gene, which is a
segment of DNA
• The two essential functions of genetic
material are replication and expression.

4. Definitions
• Genes are sequences of nucleotides within DNA
that code for functional proteins.
• The arrangement of genes within organisms is its
genotype , The order of DNA bases constitutes
the bacterium's genotype*
• the physical characteristics an organism based on
its genotype and the interaction with its
environment, make up its phenotype*
• alternate forms of genes are referred to as alleles

5. Genetic Information In Bacteria
• Chromosome : Carries properties like
virulence, pathogenicity & resistance
• Plasmid : Extra chromosomal genetic material
in the cytoplasm & Replicate independently

7. Nucleic Acids
• DNA ( deoxy ribonucleic acid ) : stores
information for protein synthesis.
• RNA ( ribonucleic acid ) : transcription &
translation of information for protein
synthesis.

10. Nucleotids : basic unit of DNA/ RNA

11. Structure of DNA.
Proposed by Watson & Crick
• The DNA molecule is composed of two chains of
nucleotides wound around each other in the
form of “double helix”.
• and the two strands in the helix are antiparallel
3to 5 / 5 to 3
• Each nucleotide contains one phosphate group,
one deoxyribose sugar, and one purine or
pyrimidine base
• The double helix is stabilized by hydrogen bonds
between purine and pyrimidine bases on the
opposite strands.

13. Nucleic acids are large
polymers consisting of
repeating nucleotide units

15. two strands in the helix are
antiparallel 3to 5 / 5 to 3
The double helix is stabilized by
hydrogen bonds between purine
and pyrimidine bases on the
opposite strands
Because of complementarity,
double-stranded DNA contains
equimolar amounts of purines (A +
G) and pyrimidines (T + C)

16. • the mole fraction of G + C in DNA varies
widely among different bacteria.

17. Structure Of RNA
Structurally similar to DNA, except for 3 major
differences:
• Single strand
• ribose sugar
• uracil in place of thymine.
3 types of RNA
• m RNA (messenger RNA)
• t RNA ( transfer RNA )
• r RNA ( ribosomal RNA

20. DNA in bacteria

21. Structure of bacterial chromosome
Bacterial Chromosome :
• It Contains a Double stranded molecules of
DNA arranged in circular form.
• Length 1,000 microns.
• Bacterial DNA contains about 4,000kilobases
• 1 kb = 1000 base pairs (A-T) (G-C)

24. PLASMIDS
• Circular DNA molecules Important vectors in
genetic engineering
• EPISOME :Plasmid DNA integrated with
chromosomal DNA.
• Their size varies from 1 kbp to over 400
kilobase pairs (kbp).
• Capable of Autonomous replication

27. May encode genetic information for
properties
1 Resistance to Antibiotics
2 Bacteriocins production
3 Enterotoxin production
4 Enhanced pathogenicity
5 Reduced Sensitivity to mutagens
6 Degrade complex organic molecules

36. Genatic Codon
• is a unit consists of sequence of three Bases
Code is triplet A-T- C
• A code can make single Amino acid
• More than one code present for making similar
sequence of Amino acid
• AGA make Arginine
• AGC, CGU, CGG, also code for similar Amino acid
• Some Codons UAA don't code for any Amino acid
called as Nonsense codon

39. Exons & Introns
• Introns : non coding sequences on a gene.
• Exons : coding sequences on a gene translated
into gene products .

41. • Prokaryotic DNA Replication

42. DNA replication is semi-conservative

54. DNA Transcription

84. Thank you
‫اهداء‬:‫وصدقة‬ ‫اهداء‬ ‫كذلك‬ ‫و‬ ‫العزيز‬ ‫والدي‬ ‫لروح‬ ‫جارية‬ ‫صدقة‬
‫الغالية‬ ‫المي‬
‫للوالد‬ ‫الغفران‬ ‫و‬ ‫الرحمه‬ ‫و‬ ‫الوالدة‬ ‫عمر‬ ‫بطول‬ ‫الدعاء‬ ‫الرجاء‬