DNA Structure

At physiological pH are nucleotides or nucleosides charged? Why?

Nucleotides because of the negatively charged phosphate group
conjugated bonds of purines and pyrimidines absorb UV light at what wavelength?

260 nm
Chargoff's rule

amount of pyrimidines is equal to the amt of purines
What molecule accounts for the repulsion between strands?

negatively charged phosphate in the backbone
Nitrogenous bases are attached to what carbon on teh ribose sugar?

1 prime
Hyperchromicity( absorbance of light) increases when
- Upon denaturation via a change in pH, temperature, salt concentration
- single strand has higher hyperchromicity because nitrogenous bases are exposed and their conjugate bonds are able to absorb UV light at 260 nm
whats melting temp of DNA, what factors influence it?
- melting temp is the temp at which half DNA is melted
- cytosine= guanosine raises the melting temp of DNA
Dideoxyribonucleotides are used in what procedure

Sanger DNA sequencing
Z helical conformation existis in regions of DNA that are rich in what nucleotides?

CG
A form of DNA is obtained how

By dehydrating B form
Whats the only form of DNA that has a Left helical rotation?

Z form
Histones are rich in what a.a , what charge do they have?

arginine, lysine positively charged to offset the negative charge of phosphate groups

Author

pszurnicki

61301

Card Set

DNA Structure

Description

DNA Structure

Updated

2011-01-23T01:19:25Z