DNA structure

Question 1

Frederick Griffith

Answer 1

studied bacteria that cause pneumonia
2 strains: R (rough)-harmless & S (smooth)-deadly
experiment:
heat the S strain=harmless
live R+heated S=deadly
Saw that there was a transforming factor that caused the R strain to turn into the S strain

Question 2

Oswald Avery (Colin McCleod and Maclyn McCarty)

Answer 2

Rationalized that there are specific macromolecules in a cell
Used enzymes to destroy each type of macromolecule in the “S” strain, theorizing that the “S” would transform into an “R” strain when its factor is destroyed
Found the transforming factor to be DNA

Question 3

Alfred Hershey and Martha Chase

Answer 3

studied bacteriophages=a viruse that attacks bacteria.
Labelled virus with radioactive isotopes: Proteins with sulfur and DNA with phosphorus
Found that DNA is the genetic information of cells

Question 4

Linus Pauling

Answer 4

Caltech professor
Nobel Prizes: proteins & peace
Was believed to be a communist because he was against the creation of nuclear weapons

Question 5

James Watson & Francis Circk

Answer 5

Watson: 23 yr old American
Crick: 35 yr old physical chemist
Used work of Rosalind Franklin & Maurice Wilkins
Discovered DNA: is 2 chains of monomers & has a twisted shape=double helix
Crick discovered they 2 chains were antiparallel

Question 6

Irwin Chargraff

Answer 6

Established the Base pair rule
In a cell:
the amount of Thymine will always match the amount of adenine
the amount of Cytosine will always match the amount of guanine

Question 7

Nitrogenous bases

Answer 7

thymine, cytosine,adenine,guanine

what holds 2 strands together

Question 8

purine

Answer 8

2 ring shape

adenine & guanine

Question 9

pyrimidine

Answer 9

1 ring shape

thymine & cytosine

Question 10

deoxyribonucleic acid

Answer 10

DNA

uses sugar deoxyribose