Hershey & Chase Flashcards
What did the experiment show…
-DNA was the hereditary material
What did they work with?
-Worked with a kind of virus called a bacteriophage
What does a phage contain…
-A phage contain a molecule of DNA surrounded by a protein coat called a capsid (doesn’t contain any other molecules)
What is a bacteriophage?
A virus that infects a bacterial cell, and causes more ‘phases to be made
A phage…
Attached to a bacterial cell
The phage does not enter the cell but something passes into the bacterial cell and causes it to make new phages
Carried out 2 parallel investigations:
1) grew phages for a long time in a medium containing RADIOACTIVE PHOSPHOROUS (32P)
2) grew phages for a long time in a medium containing RADIOACTIVE SULFUR (35S)
Proteins contain sulfur but not…
Phosphorous
In one investigation the phage protein coats became labelled with …
Radioactive sulfur
In the other investigate the phage DNA became labelled with…
Radioactive phosphorous
Bacteria did not contain…
Any radioactive atoms
In each investigation the labelled ‘phages were…
Added to bacteria
Mixture then put into a blender…
Strips off the phage coats from the bacterial cells
Mixture was then centrifuged…
A centrifuge spins material at a very high speed
The denser bacterial cells form a…
Pellet at the bottom of the tube
The less dense phage coats form layer at the…
Top of he tube called the supernatant
