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