lecture 32 Flashcards
whats horizontal gene transfer
Horizontal Gene Transfer = directly from one organism to another
whats vertical gene transfer
transfer of DNA from parent to offspring
whats a virulence factor
Virulence is described as an ability of an organism to infect the host and cause a disease. a virulence factor is something that helps the bacteria achieve this
what two strains of Streptococcus pneumoniae. did griffith find
he found a smooth strain and a rough strain
what was the difference between the smooth and rough strain
the smooth strain had a capsule where as the rough one did not
how did the capsule aid the virulence of the bacteria
it prevented the bacteria from being phagocytosed
how did the Griffith dude find evidence of horizontal gene transfer
The guy then went and put a capsule less cell and a damaged one into a rat and it resulted in the death of the organism. This showed evidence of horizontal gene transfer between two bacterial cells.
what are the three methods of horizontal gene transfer in bacteria
transduction, conjugation and translation
what is transformation
this occurs when naked DNA from a degraded bacteria moves into another bacteria. Usually occurs when the cell wall of bacteria is yet to fully form and the naked DNA can seep into the bacteria.
what time does DNA transfer normally occur
when the cell wall of a bacteria is yet to fully form and the naked DNA can seep into the bacteria
what is transduction:
horizontal DNA transfer involving bacteriophages
How does transduction occur
the bacteriophage attaches to the cell wall .when the correct ligand is felt the DNA of the phage is injected into the cell. Viruses then do their normal thing of being made within the cell and stopping the production of normal cell DNA and normal cellular proteins. In the process of piecing together the new phage, this plasmid DNA may be placed into the phage. and the virus will go onto inject this phage DNA into other bacteria
what structure does conjugation involve
the sex pili
how does conjugation work
this is the one that involves the specialised fimbriae the sex pilus. Genetic information is transferred from one bacteria to the other by this sex pilus.
whats phage therapy
therapeutic use of phages to treat and kill bacterial infections. Bacteriophages could be used to target specific bacteria and kill it potentially for us.
