bcm13 Flashcards
purines
adenine
guanosine
pyrimidines
cytosine
thymidine
uracil
what are heterocyclic compounds?
compounds with one or more carbon atoms in ring
draw cytosine
-
draw thymine
-
draw uracil
-
what do purines have in common with histidine
imidazole ring
draw adenine
-
draw guanine
-
nuceloside
base and ribose
what are the 5 nucleosides
adenosine guanosine cytidine uridine thymidine
nucleotides
base and ribose and phosphate
draw amp
-
what is dctp
draw
deoxycytidine triphosphate
- nucleotide with deoxy form of ribose`
name two coenzymes that contain adenine
fad nad
what is riboflavin?
vitamin b2
yellow compound used in practicles
what is coA’s stucture
beta mercaptomethylamine (containing s) - panothenic acid - adp
what can niacin definciency give you?
Pellegra- dermititis, diarrhoea, dementia
what is nicotinic acid, draw
pyridine ring with carboxyllic acid at position 3
what are the pkas of nicotinic acid
carboxylate 2.2
ring nitrogen 4.9
draw cyclic amp
-
what is amp?
adenosine 3’ 5’- cyclic monophosphate
what does increase in camp concentration in cell do?
active protein kinases
what does cyclic gmp act as?
an intracellular signalling molecule
- specialised functions in different types of cells
important in vision
draw cyclic gmp
-
how is cgmp synthesized?
from gtp by guanyl cyclase
what does viagra do?
blocks break down of cGMP by cGMP phosphodiesterase
what direction is dna sequence always specified in?
5’ 3’ direction of ribose
what links nucleosides?
phosphodiester bridges
what does negative charge of dna back bone prevent?
nucleophillic attack
what are the watson and crick base pairs?
adenine and thymine
guanine and cytosdie
draw out watson and crick base pairs
-
what can happen to CG base pairs in vertebrates?
they can be methylated
what is methyltion of dna bases in bacteria used to do?
block the action of restriction enzymes
what is special about methylation of dna?
it can be inherited when a cell divides and can play a role in marking which genes are active
what must a bacteria cell producing restriction enzymes also produce?
a methyl transferase to protect its own dna
draw 5-methyl cytosine
-
draw n methyl adenine
-
what do bacteriophage use methylated dna to do?
recognise own dna and stop virus dna replication
what do vertebrates use methylated dna for?
expression not protection
what does dnap require?
template strand
oglionucleotide primer
supply of deoxynucleotide triphosphate dNTPs
what does the 3’ hydroxide act as?
a nucleophile
what do chain terminators act as?
antiviral drugs
- drugs for herpes
no more bases can be added so virus cant replicate its dna
why can hiv vaccine pass through membrane?
as the azido group is lipophillic
what is udp glucose?
draw
precursor
uridine diphosphate glucose donates glucose for gycogen synthase
what does ado met act as?
s-adenosylmethionine (SAM) acts as a methy donor
what is the drug for herpes
acyclovir
contains guanine base
what is the drug for hiv with an azido group
draw
azidothymidine (AZT)
contains thymidine with azido group on 3rd carbon
what is the drug for hiv
zalcitabine
dideoxycytosine
cytosine attached to deoxy ribose
what is an azido group?
-N=N^+=N^-
what colour is fmn?
blue
flavo mononucleotide
what structure does riboflavin contain?
isoalloxazine ring
