4- biochem of nucleic acid Flashcards
(29 cards)
what is central dogma?
it’s a theory to do with flow of information from DNA being transcribed to RNA then translated to protein
what is a nucleoside?
base+sugar
what is a nucleotide?
nucleoside + phosphate group
what is nucleic acid made up of?
RNA = ribose (oxygen on carbon 2)
DNA = deoxyribose (no oxygen on carbon 2)
which is longer out of purines and pyrimidines?
purines = longer
pyrimidines = shorter
(longer name= smaller molecule)
what bases are purines?
adenine & guanine
what bases are pyrimidines?
uracil, thymine and cytosine
for base A what is:
a) name of base
b)name of nucleoside
c)name of nucleotide (for DNA & RNA)
a)adenine
b)adenosine
c)DNA = dATP (deoxy-adenosine-triphosphate) RNA + ATP
for base T what is:
a) name of base
b)name of nucleoside
c)name of nucleotide (for DNA &RNA)
a)thymine
b)thymidine
c) dTTP = DNA
TTP = RNA
for base C what is:
a) name of base
b)name of nucleoside
c)name of nucleotide (for DNA &RNA)
a) cytosine
b) cytodine
c) DNA = cCTP
RNA = CTP
for base G what is:
a) name of base
b)name of nucleoside
c)name of nucleotide (for DNA &RNA)
a) guanine
b) guonosine
c) DNA = dGTP
RNA = GTP
for base U what is:
a) name of base
b)name of nucleoside
c)name of nucleotide (for DNA &RNA)
a) uracil
b) uridine
c) dUTP
RNA = UTP
what is the only end nucleotides are added to?
3’ end of growing strand
what are nucelotides joined by?
phosphodiester bond
what enzyme adds deoxyribonucleotides and then what happens in replication?
DNA polymerase adds next nucleotide at 3’ end of growing strand and releases a phosphate
what is energy driving replication reaction?
when DNA polymerase adds nucleotide, pyrophosphate (2 phosphates joined) are released and the bond linking them is broken - releasing the energy to drive reaction
what is a phospho-diester bond?
bond formed by phosphate on 5’ end of one nucleotide connected to hydroxyl on 3’ end of next nucleotide
how do you know if RNA or DNA?
look at carbon 2 and if has oxygen then RNA and if no oxygen then DNA
what are nucleotide analogues?
they’re nucleotides that prevent replication (terminate)
-they’re incorporated into growing viral DNA and lack 3’ OH group so chain elongation terminated
why does nucleotide analogues as drugs work?
because viral reverse transcriptase has higher affinity of ZDV than human DNA polymerase (so instead of polymerase adding next nucleotide transcriptase wants ZDV)
when must DNA be replicated in mitosis?
before division of daughter cells so they have complete complement
how many origins of replication in a) eukayotes
b)bacteria
a) many
b) only 1 as smaller genomes
what means replication finished in reasonable time?
replication starts simultaneously at several points in genome = bidirectionally (results in leading strand & lagging strand)
when are replication forks created?
they’re formed at origins where DNA starts unwinding (simultaneously at each origin site) creating a space which is the repliciation fork
