Q/ where is the hereditary material found in organisms? How was this determined?
A/Hereditary material is found in the DNA rather than in PROTEINS than in organisms
Hershey & Chase- Experiment with bacteriophages (1940)
DNA incorporates phosphorus and PROTEIN incorporates sulfur. Knowing this, they used bacteriophages grown in
radioactive sulfur and radioactive phosphorus and allowed them to infect bacteria and analyzed supernatant for
remaining. They found that bacterial cell was radioactive when radioactive phosphorus is incorporated into
Q/ Describe the structure of the DNA.
A/ A two strand antiparallel with one strand running from the 5’ to 3’ and the other one in the opposite direction (wind in a
Discovered by Watson and Crick using data from Wilkins and Franklin
Nucleotides made up of alternating molecules of ribose sugar and phosphate (In DNA C2 does not have oxygen)
In C1 location is the base located
In C3 location of hydroxyl group
In C5 location of phosphate group
Q/ Difference between purines and pyrimidine
A/ Purines (2 rings, Adenine and Guanine), Pyrimidine (1 ring, Thymine, cytosine)
For the structure of the DNA to be stable the pairing of the nucleotides has to be between A-T (double bond) and
G-C (triple bond).
Two pyrimidine would be too wide. Two purines would be too narrowed. (It would not be parallel)
Q/ how is DNA replicated? Describe the experiment.
A/ Semi-conservatively. (Parental DNA splits and each strand serve as templates, F1 results in 1 strand daughter and 1
Conservative (2 strands copied at the same time and it results in 1 with strands fully parental and 1 with strands
Dispersive (Chunks of old and