purine and pyrimidin nucleotides
NUCLEOTIDE = SUGAR + BASE + PHOSPHATE
NUCLEOSIDE = SUGAR + BASE
N number of nucleotides = RNA and DNA------------------à Chromosome------Genetic password-----Genotype
DNA occurs when multiple nucleotides are bound by a 3’-5’ phosphodiester bond.
The 5’-OH group of a nucleotide is coupled to the 3’-OH group via a phosphate to form a phosphodiester bond.
Purine Bases:
Adenine
Guanine
Hypoksantine
Xantine
Pyrimidine bases :
Uracil
Cytosine
Timine
Cytosine ------ Urasil + NH3
Urasil ----- Beta-alanine + CO2 + NH3
Timine ---- +Beta-aminoisobutyrate + CO2 + NH3
The pyrimidines may also be converted to the pyrimidine nucleotides with the pyrimidine phosphoribosyltransferase.
The final product of purine catabolism in humans is uric acid. In some mammals, allantoin and even urea and ammonia may persist. The first enzyme in the destruction step is 5’nucleotidase. Phosphate is an enzyme that separates.
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