2.6 Flashcards
what are DNA and RNA monomers
nucleotides
what are DNA and RNA composed of
a pentose sugar, a phosphate group and a nitrogenous base
what is the different in the pentose sugar of RNA and DNA
DNA - deoxyribose
RNA - ribose
what are the four nitrogenous bases on DNA
Adenine - thymine
Guanine - cytosine
what are the four nitrogenous bases on RNA
Adenine - Uracil
Guanine - cytosine
what are purines
bases with two rings in their structure
examples of purines
thymine, cytosine and uracil
examples of pyrimidines
adenine and guanine
what are pyrimidines
contain only one ring in their structure
differences between DNA and RNA
DNA
contains deoxyribose
A G T and C
double stranded molecule
RNA
contains ribose
A G U and C
single strnaded molecule
what is the base attached to in the nucleotide
base is attached to the sugar
phosphate to the sugar
how do nucleotides link together
phosphodiester bonds, covalent bonds to form a single strand
phosphodiester bonds from between the phosphate group attached to the 5 carbon and the hydroxyl group attached to the 3 carbon of another sugar
what carbon is the phosphate attached to
te 5 carbon
what carbon is the hydroxyl group attached to
the 3 carbon of another sugar
what forms between the phosphate and hydroxyl group
phosphodiester bond
what attaches to the base
carbon 1
what bases pair together
guanine with cytosine
thymine with adenine
how are the strands held together
hydrogen bonds
how many hydrogen bonds are there between G and C
3
how many bonds are there between A and T
2
how do the bases face each other
the strands are antiparallel
one strand from 5 to 3 and the opposite from 3 to 5
what did Rosalind Franklin produce
DNA X ray diffraction patterns
how did Crick and Watson use Rosalinds findings
they used the DNA X ray diffraction to deduce that the DNA molecule must have a regular double helix structure
what did chargaff find
the base ration
shoed that A = T and C + G
