The Molecular Basis of Inheritance Flashcards
Frederick Griffith
Was studying pneumococcus bacteria that produces pneumonia
What kind of organisms are bacteria
Single celled prokaryotes
What organism did Frederick Griffith experiment on
Mice
How many strands of a bacterial species did Frederick Griffith find 
2
What are the two types of strains that Griffith discovered
S train and R Strain
The S in s strain means
Smooth
What does the R in the R strain stand for
Rough
S strain
Disease causing bacteria grew into smooth colonies and culture plants
R strain
Harmless patriot that grows into rough conloies
Which strain of bacteria killed the mice when it was injected
S strain
How many experiments did Griffith have
4
What was Griffiths first experiment
Rough strain injected
What was Griffith second experiment
Smooth strain injected
What was Griffiths third experiment
He killed smooth strain injected
What is Griffiths fourth experiment
Rough strain and heat killed smooth strain
What happens in Griffiths first experiment
The mouse lives
What happens in Griffith second experiment
The mouse dies
What happens in Griffiths third experiment
The mouse lives
What happens in the fourth experiment
The mouse dies
How did Griffith kill the bacteria with heat
Here is the kinetic energy to break apart the strain
Transformation
Process in which one strain of bacteria is changed by a gene or genes from another strain is bacteria
What did Griffith conclude from his first and second experiment
The cause of pneumonia is not a toxin from the bacteria
 what did Griffiths include from all of his experiments
There was a transforming factor
Does Griffith discover with the transforming factor is
No
 How does Griffiths make his final conclusion
He took a blood sample from experiment 4 and found live S strain in the blood
Oswald Avery
Leader of a team of scientists at Rockefeller institute which did Griffiths for the experiment four more times
What was the main goal of Oswald Avery
Determine which molecule in the heat killed bacteria is most important for transformation
What is the first step of Avery’s method
Extracting various macromolecules (carbs,lipids, proteins, DNA) from the heat killed bacteria (each in diff steps in order to see which one would cause there to be no transformation) by hydrolyzing them with enzymes
How many times did ever use his method
4
Why did Avery repeat his method four times
To kill each of the four macromolecules
What happened when Avery killed DNA
Transformation did not occur and the mouse did not die bc the r cells didn’t turn into s (bad) cells
What did Avery conclude from his experiments
Avery concluded that the nucleic acid DNA stores and transmits genetic information from one generation of bacteria to the next
Did Avery immediately publish his work
No because Avery was afraid of backlash from the scientific community because many scientist thought that proteins were the most important macromolecule
Bacteriophage
A kind of virus that infects bacteria by injecting its genetic material into it
Bacteriophages are also known as
Phages
How many macromolecules make up phages
2
What macromolecules make up bacteriophages
Proteins which make up the head and DNA which is in the head
Alfred Hershey and Martha Chase
Studied a bacteriophage that was composed of a DNA core in a protein coat
What is the main goal of Alfred Hershey and Martha Chase
To determine which part of the virus - the core or coat - enter the bacteria
How did Chase and Hershey solve their question
They grew viruses containing radioactive isotopes of phosphorus 32 and sulfur 35 because proteins contain almost no phosphorus and DNA contains no sulfur
What was the purpose of the radioactive isotopes
The phosphorus 32 and sulfur 35 acted as markers because if they found either in the bacteria it signifies which part got injected
DNA is also known as
The molecule of inheritance
What did Hershey and chase conclude from the experiment
There was radioactive phosphate inside of the bacteria so they were able to conclude that DNA is the molecule of inheritance and is found in all genes
Capsid
head of bacteriophage made of protein
