Nucleic Acids and Chromosomes Flashcards
1
Q
Which bases are purines and which are pyrimidines?
A
AG = purines CUT = pyrimidines
2
Q
How many base pairs are there per helical turn and how wide is the double helix?
A
10 bp per helical turn 2nm
3
Q
State two ways of separating the DNA strand.
A
Heat Low salt concentration
4
Q
What is the lowest level of packing of DNA?
A
Nucleosome – it is wrapped around a histone (positively charged) which strongly attract to the negatively charged backbone of DNA – 200bp – causes 7 fold condensing
5
Q
What is the next level of packing of DNA?
A
30nm fibre
