Lecture 2 Flashcards
What identifies chromosomes as the carriers of genes?
Chromosome theory of inheritance and Mendel’s studies
Why are proteins more complex?
Because proteins have 20 amino acids
What are chromosomes made of?
Proteins and DNA
What did Fred Griffith study?
Pneumonia
What does Streptococcus pneumonia form?
A diplococcus where a pair of cells remain attached due to incomplete cell division
What changed in Griffiths experiment?
Rough looking colonies of diplococcus
What is the characteristics of the Smooth strain of of Pneumonia?
- Smooth colonies form pneumonia
- Kill mice
- glycocalyx protects bacteria from mouse immune system
What are the characteristics of the Rough strain of Pneumonia?
- Rough colonies do not cause pneumonia
- not virulent because they lack the protective glycocalyx
- Look rough because they look glycocalyx
What is Griffiths experiment killed the mice?
The S-strain and the heat killed S strain combined with the R strain
what was the conclusion of Griffiths experiment?
That there was something in the heat inactivated S-cell bacteria that was taken up by the R strain that restored the virulence to the R strain that now looked like the S strain. This is called the transforming principle
What does DNA competence?
It means that a cell has the right facilities to accommodate the DNA
How can researches change bacteria in the lab?
A researcher can modify the bacteria to be competent by adding receptors and then add DNA
How did Avery figure out what was responsible for the transforming principle?
He destroyed different parts of the bacteria and repeated the experiment
What substance is responsible for the transforming principle?
DNA
How does Bacteria replicate?
Bacteriophages injects itself in the bacteria and replicate which produces more bacteriophages
How did Hershy and Chase confirm the transforming principle?
By marking the DNA is phages before they infect bacterium and seeing which one was injected inter the bacteria
what are the things that DNA must be able to do if it is the hereditary material?
Replicate
Carry information
Control cell activity
Mutate