chapter 8 Flashcards
What was the carrier for genetic information?
chromosomes and they are made up of protein and dna
who led to the discovery that DNA carrie’s genetic info?
Griffth based on his pneumonia study
what is the difference between R strain and S strain?
A R strain is not surrounded by a capsule and doesn’t cause pneumonia. The S strain is surrounded by a capsule and allows bacteria to evade the immune system.
Conclusion from Griffth’s experiment on pneumonia.
Living R strain cells had transformed into S cells so into passed from dead S to living R. The carrier of the genetic info is transforming factor.
what did Avery, MacLeod, and McCarty discover?
That the transforming factor that allowed transformation was DNA
What is the basic building blocks?
Nucleotide
what are the three components of nucleotide?
nitrogen containing base (4), sugar (deoxyribose in DNA), phosphate group
Purines vs pyrimidines
adenine and guanine (purines)
cytosine and thymine (pyrimidines)
What did Watson and Crick determine?
They determined the structure of DNA by sifting through info about DNA that was already available
What did Franklins diffraction photograph tell us?
DNA has a helical shape with a constant diameter and that phosphate groups were on the outside of the helix while nitrogenous bases were stacked inside
Watson and Crick Model of DNA
DNA is made up of two polynucleotide chains. Sugar and phosphate backbone with nucleotide rungs. Chains run in opposite directions. Strands are complementary.
How many hydrogen bonds for each pairing ?
A to T (2 hydrogen bonds)
C to G (3 hydrogen bonds)
How does DNA store information?
The four bases allow for a high coding capacity. DNA is stored in the orders of the bases. A complete set of genetic information is a genome.
Organization of dna into chromosomes
Chromosomes uncoil and recoil during cell cycle. Must be uncoiled to replicate and coiled to go through mitosis
chromosome organizing
within chromosomes, DNA is cooled around clusters of histone proteins to form nucleosomes
