Nucleotides Flashcards
Formed of
Nucleoside+phosphate
N base+ pentose+ phosphate
(Pyrimidine/purine)
(D ribose/ deoxy ribose)
Major pyrimidine
Cytosine(2 oxy 4 amino pyrimidine)
DNA +RNA
Uracil(2,4 dioxy pyrimidine)
RNA
Thymine (5methyl uracil)
DNA + minor in tRNa
Mino pyrimidine
Dihydrouracil(tRNA)
5methyl cytosine(human and bacterial DNA regulation)
5hydroxylmethyl cytosine(viral DNA)
Purine ring structure
Pyrimidine+ imizadole ring
Major purines
Adenine(6 aminopurine)
Guanine(2 amino 6 oxypurine)
DNA &RNA
Minor purines(human RNA)
7 methyl guanine
N6 methyladenine
N6N6 methyl adenine
mRna as minor base
Oxypurines
Hypoxanthine>6 oxypurine(catabolism of adenine) (mino tRNA components)
Xanthine>2,6dioxy purine(catabolism of guanine)
Uric acid>2,6,8 trioxy purine(final product)
Present in free form or in nucleotide
Rarely in nucleic acid
Transformation enzyme
Xanthine oxidase enzyme
Gout
Normally 3-7 mg/dl
Hyperuricemia
Medicine is allopurinol that inhibits xanthine oxidase enzyme
Methylated purines of dietary origin
Diuretics
Caffeine (coffee)(1,3,7 trimethyl xanthine)
Theophylline(tea)(1,3 dimethyl xanthine)
Theobromine (cocoa) (3,7 dimethyl xanthine)
CNS stimulators
Smooth muscle relaxants
Why methylated purines are contraindicated with gout
As their catabolism does not produce uric acid which is a major characteristic in gout patients
Pentoses
DNA (deoxyribose)
RNA(ribose)
Furanose ring in beta form
Naming of nucleosides
Naming of nucleotides
Adenine>adenosine>adenosine monophosphate
The linkage
N-base + sugar> N glycosidic bond
Sugar+ phosphate> ester bond
Sugar with base with c? With n?
C1’
N1 pyrimidine
N9 purine
Sugar with phosphate
C5’
Alcohol+ acid (phosphatidic acid)
Naming table
Adenine
Guanine
Xanthine
Hypoxanthine
Cytosine
Uracil
Thymine
Adenosine>adenosine monophosphate
Guanosine>guanosine monophosphate
Xanthosine>xanthosine monophosphate
Inosine>inosine monophosphate
Cytidine>cytidine monophosphate
Uradine>uradine monophosphate
Thymidine>thymidine monophosphate
Or acid
List the nucleotides containing adenosine
AMP
ADP
ATP
cAMP>cyclic 3’ 5’ adenosine monophosphate
PAPS> 3’phosphoadenosine-5’ phosphosulfate
Nucleosides with adenosine
SAM
S-adenosyl methionine
The nucleotide with adenine that is a second hormone messenger
Formed by…
cAMP
Adenyl cyclase action on ATP
Methyl donor
Sulfur donor
SAM >ATP (adenosine)+ methionine
PAPS
Knowing the pyrimidines
=O»_space;>
Uracil
CH3, thymine
No double bonds, dihydrouracil
No O on top»
Cytosine
CH3, 5methyl cytosine
OH, 5hydroxymethyl cytosine
Adenine nucleotides
AMP/ADP/ATP/cAMP
ATP(adenosine donor)>cAMp/SAM(methyl donor)/PAPs(sulfur donor)
Co enzymes with adenine
Hydrogen carriers> NAD/NADP(nicotinamide adenine dinucleotide)
FMN/FAD(flavin adenine dinucleotide)
Acyl carrier>coenzyme A, carries acyl group on thiol group
Coenzyme without adenine
FMN
flavin mononucletide
Riboflavin is
Vitamin B2
Guanine nucleotides
GMP/GDP/GTP
GTP>cGMP by guanylyl cyclase enzyme
cGMP
3nd hormone messenger
May be antagonistic to cAMP
Vasodilation by activating guanylyl cyclase
Used for sildenafil(vigera) for men
Cytosine nucleotides
Cytidine phosphate carries
Ethanolamine/choline/diacylglycerol
Used for phospholipid synthesis
Uracil nucleotides
UDP carries
Glucose(glycogen/glycoproteins)
Galactose(lactose)
Glucuronic acid(GAGs/steroids/bile pigmentation/drugs/ increased solubility/help in excretion)
