principles of MB Flashcards
1
Q
when was hershey chase experiment and what did it show?
A
- that DNA is hereditory material not proteins. using bacteriophages (P32 dna)(S35 protein)
2
Q
what were DNA and proteins labeled with and why?
A
DNA (P32)- phosphate in DNA no protein
proteins (S35) - sulphur in proteins not DNA
3
Q
what is DNA made up of?
A
NUCLEOTIDE monomers — phosphate head, sugar (pentose ) group and notrogenous base/group
4
Q
what carbons are phosphate and nitrogenous base attached to?
A
phosphate - 5
nitrogenous base - 1
5
Q
what is difference between purine and pyramidine?
A
purine - 2 rings (adenine, guanine)
pyrimidine - 1 ring (cytosine, thymine, uracil)
6
Q
what is chargaffs rule?
A
DNA has to be 50% purine, 50% pyrimidine
7
Q
when and who proposed double helix model?
A
watson and crick 1953
8
Q
how are nitrogenous bases held together?
A
hydrogen bonds,
2 bonds between A and T
3 bonds between C and G
