Lecture 15 Flashcards
Which macromolecule was initially thought to be the bearers of genetic information?
Proteins, NOT DNA
What were the two main observations from Chargaff’s experiments? What conclusion could he then make? Which observation was this conclusion based on?
- The approximate concentrations between A & T and G & C were equal as shown by data. within the same species
- The composition of the DNA was different between species.
- Based off the second observation, he could conclude that due to the significant DNA variation between species, DNA could be the bearers of genetic information.
What do the 4 results from Griffith’s suggest about DNA?
It suggests that the bearer of genetic information was a chemical substance.
What does the ‘transforming principle’ mean?
It is pre-cursor term for DNA essentially. A transforming factor caused the Bacteria strain to transform into a virulent bacteria strain.
What was the purpose of Avery’s experiment?
Was to find out what was the chemical substance that was causing the results that Griffith show
From the results of Avery’s experiments collectively, what do they suggest?
It suggests that the neither the proteins or RNA were the carriers of genetic information, but rather the DNA were.
What was Avery’s conclusion?
DNA is the chemical substances that causes transformation. (i.e it is the genetic material.)
What are the two types of bases, and which bases belong to which? How do we distinguish between the two?
Pyrimidines : C & T
Purines: A & G
Pyrimidines have one ring structure, Purines have 2 rings.
How does the sugar differ between RNA and DNA?
Sugars in RNA has an OH group attached to the 2nd Carbon of the ring.
Sugars in the DNA has a H group attached to the 2nd carbon of the ring.
What type of bond forms between nucleotide monomers?
Phosphodiester Bonds
What is the phosphodiester bond between?
The OH group on the 3rd Carbon – P group on the 5th Carbon.
How is the DNA helix stabilised? (What subunit of a nucleotide is involved, what sort and number of bonds form between them?)
Bonds between bases help to stabilise DNA helixes
Hydrogen Bonds are involved
A-T –> 2 H bonds
C-G –> 3 H bonds
