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11 Cards in this Set
- Front
- Back
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what kind of chromosomes do bacteria have
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double stranded circular DNA, usually just one
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explain bacterial plamids
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not always present, separate from DNA, encode for toxins, antibiotic resistance
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how are bacterial DNA differ from human
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no introns or exons, circular, haploid, no histones, smaller 1.3mm vs 990mm
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what is an operon
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a group of genes that is expressed by a promotor and transcribed together
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bacteria have only one chromosome so mutation can be detrimental, what are the repair mechanisms
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Direct DNA repair (replace incorrect nucleotide)
Excision repair (cut out entire fagment) Postreplication repair (damaged spot is skipped over during replication, other strand fills in this gap, bad section is excised out and both gaps are filled in .SOS response (responds when cell cells is damaged) Error-prone repair (fills mistakes in randomly as a last resort) |
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what is an episome
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a plasmid that integrates into the DNA
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what are the three methods for bacterial genetic exchange
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transformation, transduction, conjugation
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transformation in bacteria
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uptake of extracellular DNA by bacteria
not all bacteria can take up DNA, some are naturally competent while others can be made competent |
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transduction
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bacteriophage infects bacteria lytically, DNA replicates, builds new bacteriophages, uptakes bacterial DNA, lysis, BP injects bacterial DNA into new bacteria. Generalized (Donor DNA has equal chance of phage uptake) Specialized (high chance of certain section of donor DNA being packaged
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conjugation
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bacteria with F plasmid can made a sex pilus and exchange DNA with another bacteria
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what are the possible properties of plasmids
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drug resistance (R-factors)
• virulence factors – toxins – adhesins – growth factors – antimicrobial agents – metabolic activities – surface antigens |
