Chemistry of Nucleotides - incomplete Flashcards
what are the roles nucleotides serve in metabolism
building block of ATP
key to synthesis of coenzymes
not an energy source
what are nucleotides composed of
inorganic phosphate
5-carbon sugars (ribose or deoxyribose)
nitrogenous base (purine or pyrimidine)
which type of bond connects the base to the sugar ring of a nucleotide
which carbon is linked to the base
glycosidic
C1’
how many hydrogen bonds present in:
guanine - cytosine pairing
adenine - thymine pairing
GC: 3
AT: 2
which base pairing is stronger GC or AT
GC
more H bonds
what does it mean that are two kinds of bases in a base pairing
what does it result in
6-membered ring and a 5-membered ring pair (purine and pyrimidine always pair never with themselves)
consistent space between them
which bases are purines
what is their structure
adenine
guanine
two rings
which bases are pyrimidine
what is their structure
cytosine
thymine
uracil
one ring
nucleoside definition
a glycosylamine
base linked to a sugar by a beta-N-glycosidic bond
why is a nucleoside more water soluble than its free base
what is the effect of the similarity of uracil and cytosine
why does DNA need thymine
what are the physiological roles of adenoSINE
plays a role in signalling (cAMP)
inhibitory neurotransmitter in the brain (depressant)
what causes the feeling of tiredness and promotes sleep
what is the action of caffeine
blocks the adenosine receptor in the brain preventing sleep
