nucleic acid Flashcards
a nucleoside has what two components
sugar and base
what is the difference between a ribose and deoxyribose?
on the 2’ carbon ribose has OH
it is the ___ that determines whether the nucleic acid is DNA or RNA
sugar
the 3’ OH on carbon of nucleic acid reacts with?
dNTP
the OH on ribose 2’ carbon makes what difference in reactivity
the ribose is more reactive and therefore less stable
the ribose strucker is ____ which allows for movement and more reactions
puckered
the purines have one or two aromatic group (pure as gold)
two
guanine has what two distinctive features as opposed to adenine
double bonded oxygen (6’) and NH2 (2’)
where is a purines point of attachment
9’ NH
where is a pyrimidines point of attachment
1 pyrimidine
what are thymines to unique properties as opposed to cytosine and uracil
CH3 (5’) and double bonded O (4’)
the sugar and the base are attached by what bond?
N-b-glycosidic bond?
attachment of phosphate is at ___ carbon
5’
the ___ ____ links C3’ OH of one nucleotide to C5’-phosphate of the next
phosphodiester bond
Two reasons RNA is less stable than DNA
it is single stranded and therefore open to degradation (base-catalyzed hydrolysis) and reactive OH
____ strand absorbs more UV light
single
what is chargaffs rule
A+G=C+T
what is the most important factor in stability for double helix
base stacking
C=G have how many hydrogen bonds
C-G
the strands of DNA run __ ___ and are complimentary
anti parallel
bases being in anti conformation allows for less steric henderence and allows for rotation around _ _____ bond
N-glycosidic
left handed helix, more extended and formed by particular base sequences
z form
watson and crick DNA structure, right handed helix (most stable)
B form
found in relative absense of H20, right handed helix, wider and more compact (crystallization)
A form
