nucleic acids Flashcards
(35 cards)
nucleotide
nucleic acid monomer
1. phosphate group
2. nitrogenous base (A, U, G, C, or T)
3. pentose sugar
nucleoside
only pentose sugar and nitrogenous base
difference between RNA and DNA pentose
rna has 2’ OH whereas DNA is missing 2’OH
purine
A and G
- 2 rings
pyrimadines
T, U, C
1 ring
uracil structure compared to thymine
demethylated version of thymine
how do adenine and guanine differ
adenine (amine) guanine (carbonyl group)
what differentiates cytosine from other pyrimidines
only pyrimadine with a primary amine
phosphate group
PO4 3-
- interact with 3’ and 5’ OH to form phosphodiester bonds
3’ OH
points down
5’ OH
points up
nucleoside diphsophates
have two phosphate groups attatched
nucleoside triphosphate
has 3 p groups
adenosine triphosphate
ATP
- adenine, bound by 3 phosphate groups
similar to gtp
3’5’ - cyclic adenosine monophosphate
CAMP
phosphideister bonds
bond between p group and 3’ or 5’ end of sugar
C-O-P-O configuration
nucleotide cofactors
FAD, NAD, FMN, NADP, coA
viral genome
can be double or single stranded dna or rna
base pairing
c—g
a–t
a–u
how many hydrogen bonds are in the G-C bond
3
how many hydrogen bonds are in the AT bond
2
chargoff’s rule
purines and pyrimidines exsist in a 1:1 ratio (DNA only)
amount of g = amount of c
amount of a = amount of T
purpose of hydrogen bonding between nitrogenous bases
stabilizes the double stranded structure
base stacking
hydrophobic interaction between nitrogenous bases on the same strand