Transformation Flashcards
What is the general mechanism of transformation?
A process by which genetic information is taken up by competent bacterial cells.
How does transformation occur in Streptoccocus pneumonia.
Environment (stress conditions) signal a small portion of the population to become competent. These competent cells capture foreign DNA via the transformation pillus. The DNA is passed to a protein complex, then a nuclease. Where one strand of the DNA is degraded, once in the cell the ssDNA can be integrated into the cells chromosome
What is the role of transformation in the lifestyle of Streptoccocus pneumonia.
Competence occurs in only a low proportion of the population, is a high-energy state, also the uptake of DNA isn’t always positive.
In streptococcus can result in antibiotic resistance and changes in capsular type.
Describe the experiment that suggested transformation in bacteria.
Used rough and smooth (r and s) strains of bacteria. Smooth being pathogenic, and rough being benign. Would kill smooth bacteria via heat sterilisation, and introduce the lysis mixture to the rough strain. Then when introducing the rough strain to mice it would be pathogenic.
