DNA Flashcards
What is DNA?
DNA is a polymer that is located in the nucleus of a cell.
It is short for Deoxyribonucleic acid.
What is DNA composed of?
DNA is composed of a long chain of nucleotides (the building blocks for DNA and RNA is all you need to know for now).
Ok. What is a nucleotide composed of?
It is composed of: 5-carbon ring sugars, Phosphate groups and one of four nitrogenous bases.
What are those 4 nitrogenous bases?
Adenine (A), Guanine (G), Thymine (T) and Cytosine (C).
What did Griffith do that was so important?
He helped pioneer the argument that DNA contains genetic information.
What did Griffith do in his experiment?
He injected mice with two different strains of Pneumonia, one lethal and one non-lethal.
On top of that he injected a heat killed lethal strain and a combination of the heat-killed lethal strain and live non-lethal strain.
What happened to mouse who was injected with the combination strain?
It died :(
Why is this important to understanding the concept?
Somehow the genetic info from the heat killed strain was transferred to the non-pathogenic strain and duplicated, making it very lethal. It was called the ‘transformation’.
Demonstrated that some information existed which could be inherited.
What does DNA look like?
Looks like a double stranded spiral thing (the twisted ladder we are used to seeing).
What happens when everything is merged?
Remember A.C.T.G? The order it’s in determines the specific proteins and enzymes that will be produced.
What does DNA look like? (in more detail)
A twisted ladder with sugar and phosphate forming as the ‘backbone’ on the outside of the ladder.
The nitrogenous bases (A, C, T and muh G) form rungs (rungs are the steps).
Hydrogen bonds link the two sides of the ladder together.
What does all this mean?
(what is the limitation?)
Well due to the structural formation of the nitrogenous, it places a restriction which allows them to only bond to certain other bases.
They are called ‘Complimentary base pairs.
REMEMBER:
**Adenine goes with Thymine and Guanine goes with Cytosine. **
What is the structure of DNA called?
It is called the ‘anti parallel double helix’.
