DNA Structure and Synthesis COPY COPY Flashcards
Describe transformation
when one bacteria changes the characteristics of another
How did transformation lead to the discovery of DNA?
It was discovered that DNA was the transforming factor
What is a bacteriophage?
a virus that uses a bacteria to replicate itself
How did bacteriophage help confirm the role of DNA?
the virus injects DNA into the bacteria to replicate itself which showed that DNA stored genetic information
What is X-ray crystallography?
early technique used to get a visual of DNA
How does X-ray crystallography work?
it diffracts light through a DNA crystal which creates an image
Describe DNA structure
double helix which runs anti-parallel
Describe double helix
two strands twisted around each other
Describe anti-parallel
3’ and 5’ ends run opposite directions
What makes up a nucleotide
base, sugar, phosphate
What makes up a nucleoside
base, sugar
Pyrimidines have ___ ring (s)
one
Purines have ___ ring (s)
two
Pyrimidines consist of what bases?
cytosine, thymine, uracil
Purines consist of what bases?
adenine, guanine
What do Chargaff’s rules state
in any species there is an equal number of A and T bases, and an equal number of G and C bases
Purine + purine would impact the DNA structure how?
too wide
Pyrimidine + pyrimidine would impact the DNA structure how?
too narrow
What is the correct model of DNA replication?
semiconservative model
Describe the semiconservative model
replicated DNA will have one old and one new strand of DNA
Describe the conservative model
the two parent strands rejoin