1. CHAPTER 8 MICROBIAL GENETICS: BIO 244 MICROBIOLOGY
the structure of _______
how ______ carry information
how information is _________
and how _______ are replicated

2. GENETIC TERMINOLOGY
_______ segment of ___ that codes for a trait or product, usually a protein _____TYPE genetic makeup (genes) of an organism ______TYPE expression of genes

3. BACTERIAL __________

4. _________ CHROMOSOMES
__________
_ CHROMOSOMES
_________ CHROMOSOMES

5. _________ ACIDS _________ ________ Information Molecule
Double-stranded
helix of nucleotides
Protein
Synthesis
Single-strand
of nucleotides
Energy
Storage
Single
nucleotide

6. _______________ Polymer of __________: 1.phosphate 2.sugar
3._____ (adenine, thymine,
cytosine, guanine)
Double Helix: associated
with proteins
"Backbone”:
deoxyribose-phosphate
__________ Bonds:
found between AT and CG;
hold strands together
____________ strands
Figure 8.4

7. DNA REPLICATION semi-_____________ mechanism
Double-stranded helix __________
Each strand serves as a ________ for synthesis of new strand
Each new double-stranded DNA helix contains:
One original strand from parent
One new strand
Figure 8.3

8. Semi-conservative Replication of DNA

9. DNA REPLICATION SUMMARY Semi-Conservative Mechanism
DNA is copied by DNA _______________
In the _________ direction
Initiated by an RNA primer
_________ strand synthesized continuously
________ strand synthesized discontinuously
Okazaki fragments
RNA primers are removed and Okazaki fragments are joined by _______________ and DNA ligase

10. DNA SYNTHESIS
Figure 8.6

11. RIBONUCLEIC ACID (RNA)
TYPES of RNA:
Messenger RNA (mRNA)
Complementary to base sequence in ______
Carries genetic information from DNA to ribosomes
Ribosomal RNA (rRNA)
Makes up ___________
Functions in protein synthesis
Transfer RNA (tRNA)
Transports __________ to growing peptide chains in ribosomes
FUNCTION: protein synthesis
STRUCTURE:
Single-stranded chain
of nucleotides
_________ replaces thymine
Ribose sugar

12. Big Picture pg. 202 (2 of 9).

13. PROTEIN SYNTHESIS 2 Step Mechanism: 2. ____________
- Takes place in the ribosome
- Information in mRNA is translated into a sequence of ________________
- Involves mRNA, ribosomal RNA (rRNA) and transfer RNA (tRNA)
1. ________________
- Takes place in the ____________
- _________copy of DNA-base sequences is made
- Involves DNA and messenger RNA (mRNA)

14. TRANSCRIPTION -Involves ____ and ____ -Takes place in the nucleus
1. RNA polymerase binds to promoter sequence in DNA
2. mRNA is made by complementary base pairing of free nucleotides with the nucleotide bases on the template strand of DNA
3. DNA that has been transcribed __________
4. Messenger RNA and RNA polymerase are released and DNA helix reforms

15. ______ and CORRESPONDING AMINO ACIDS
CODON- a sequence of 3 bases
in _______ molecule:
-Specifies a single amino
acid
Start codon = AUG-specifies the start of protein synthesis
Stop codon = UAA, UAG, UGA-specifies the end of protein synthesis
-Universal
All species use same mRNA codons to specify same amino acids
Figure 8.9

16. __________________ Information in mRNA is translated into a sequence of ___________ that result in proteins
-Takes place at the ribosome
-Involves __________________
-Information for each amino acid is contained in mRNA codons (3 nucleotides)
-Translation of mRNA begins at the START codon: AUG
-Translation ends at a STOP codon: UAA, UAG, UGA
Figure 8.2

17. The Process of Translation
Figure 8.9

18. The Process of Translation
Figure 8.9

19. The Process of Translation
Figure 8.9

20. The Process of Translation
Figure 8.9

21. GENE _____________
The majority of genes within a cell do function most of the time
Some genes __________________
Some genes ______________________
Two major types of genes:
STRUCTURAL:
Contain information that code for amino acids
REGULATORY:
Control expression of structural genes
Model representing structural and regulatory genes in prokaryote:
LAC OPERON: a model representing regulation of gene expression

22. _______________ Groups of genes that interact as a unit to control the use or synthesis of metabolic products
Model representing structural and regulatory genes in prokaryotes.
Model representing regulation of gene expression in prokaryotes.
Figure

23. _____________ OPERON Model for ___________ gene regulation in prokaryotes Represents induction of enzymes involved in lactose catabolism
FEATURES:
Regulator (I) gene – codes for
repressor protein
Lac Operon
_________ region
Promotor - where RNA polymerase initiates transcription
Operator – on/off switch for transcription
__________ Region
Genes for three enzymes involved in lactose catabolism
Induction-process
that _______ gene transcription

24. REGULATION of GENE EXPRESSION: Repression of Lac Operon
________ gene expression and synthesis of
one or more enzymes
Figure

25. REGULATION of GENE EXPRESSION: ___________ of Lac Operon
Figure

26. INDUCIBLE OPERON – Lac OPERON
____________________
If enzyme substrate (lactose) is absent –
no enzyme synthesis
Repression protein binds to operator –
no transcription of enzymes
__________________
Enzyme substrate (lactose) present –
enzyme synthesis
Repressor binds to ___________, not operator – enzymes are transcribed
Inducible transcription of enzymes

27. Enzymatic Regulation of Gene Expression
Enzymes involved in gene expression:
____________ enzymes
Expressed at a fixed, constant rate
Ex.: enzymes of glycolysis
Repressible enzymes
Inducible enzymes
Not always needed
Regulated by mRNA transcription

28. CATABOLIC REPRESSION
Ability of ____________ to repress enzymes needed for lactose utilization (catabolism)

29. MECHANISMS of GENETIC REGULATION
___________
GENETIC _____________
Transformation
Conjugation
Transduction
TRANSPOSONS

30. ______________ Change in genetic material
Mutations may be neutral, beneficial or harmful
MUTAGEN: agents that cause mutations; agents that alter DNA:
_________________
Ultraviolet (uv) -causes harmful covalent bonds between adjacent pyrimidine bases
Ex.: thymine dimers
___________
Nitrous Acid – changes nucleotide base pairs.
Ex. A is changed; binds to C instead of T
Nucleoside analogs
SPONTANEOUS MUTATIONS: occur in the absence of a mutagen

31. GENETIC TRANSFER and RECOMBINATION
________ Gene Transfer:
Occurs during reproduction, between generations of cells
Transfer of genes between cells of the same generation
RECOMBINATION
________________
______________

32. _______________
Figure 8.25

33. GENETIC EXCHANGE in BACTERIA Natural processes by which bacteria can gain new genetic material
TRANSFORMATION
DNA is taken up from _______________
CONJUGATION
Plasmid (extrachromosomal DNA) is taken up from environment involving ______________
TRANSDUCTION
_________phages act as vectors of DNA transfer between bacteria

34. ______________________
Figure 8.24

35. _______________
* ___ plasmids are one type of plasmid
Figure 8.27a

36. Recipient bacterial DNA
______________
Phage protein coat
Bacterial chromosome
Recombinant 1
A phage infects the donor bacterial cell. 2
Phage DNA and proteins are made, and the bacterial chromosome is broken down into pieces.
Bacterial DNA
Donor bacterial DNA
Recipient bacterial DNA
Phage DNA
Recipient cell
Recombinant cell 3
Occasionally during phage assembly, pieces of bacterial DNA are packaged in a phage capsid. Then the donor cell lyses and releases phage particles containing bacterial DNA. 4
A phage carrying bacterial DNA infects a new host cell, the recipient cell. 5
Recombinant can occur, producing a recombinant cell with a genotype different from both the donor and recipient cells.
Figure 8.28

37. __________________