Bacterial Transformation ; SOGM 1 Flashcards
Evidence from Bacterial Transformation
Conducted by Grifith
Model Organism
Streptococcus Pnemonae
Streptococcus Pnemonae exists in ——-strains
2
2 strains of Streptococcus Pnemonae
Smooth and Rought
Smooth Streptococcus Pnemonae is
Pathogenic
Rough Streptococcus Pnemonae
Non Pathogenic
Experiments: Step 1, what happens when Live R strain is injected in mice
Mice lived
Live S strain injected in mice
Mice died (S is pathogenic)
Heat killed S
Mice lived
Live R + Heat killed S (case no 4)
Mice Died
In 4th case, why did the mice die when S was heat killed/
This concluded that some material got transformed to LIVE R strain and made it pathogenic
Who continued this experiment?
Avery, Mcleod, Mcerty
Avery, Mcleod, and Mcerty proved that
DNA is the genetic material that got transformed from heat-killed S to Live R strain and made the mouse die
What did Avery, Mcleod, and Mcerty do?
Avery, Mcleod, and Mcerty isolated Protein, DNA, and RNA
If you want to cut something/remove something, like want to remove/cut protein, then which enzyme will you add?
Protease
To cut/remove DNA
DNAase
To cut/Remove RNA
RNAase
So, what happened when protease was given to the 4 cases of mouse
Nothing happened, no changes
What happened when RNAase was given?
Nothing happened, no changes
What happened when DNAase was given?
When you gave DNAase, the DNA got removed. Hence in case 4, the mouse survives. as the pathogenic nature of S was not able to transform to live R
What did this further experiment conclude?
They discovered that protease and RNAase have no effect on transformation but DNAse prevents transformation
