Nucleotides are organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver.
In biochemistry, a ribonucleotide is a nucleotide containing ribose as its pentose component. It is considered a molecular precursor of nucleic acids. Nucleotides are the basic building blocks of DNA and RNA. Ribonucleotides themselves are basic monomeric building blocks for RNA. Deoxyribonucleotides, formed by reducing ribonucleotides with the enzyme ribonucleotide reductase (RNR), are essential building blocks for DNA. There are several differences between DNA deoxyribonucleotides and RNA ribonucleotides. Successive nucleotides are linked together via phosphodiester bonds.
A salvage pathway is a pathway in which a biological product is produced from intermediates in the degradative pathway of its own or a similar substance. The term often refers to nucleotide salvage in particular, in which nucleotides are synthesized from intermediates in their degradative pathway.
Inosinic acid or inosine monophosphate (IMP) is a nucleotide. Widely used as a flavor enhancer, it is typically obtained from chicken byproducts or other meat industry waste. Inosinic acid is important in metabolism. It is the ribonucleotide of hypoxanthine and the first nucleotide formed during the synthesis of purine nucleotides. It can also be formed by the deamination of adenosine monophosphate by AMP deaminase. It can be hydrolysed to inosine.
Purine nucleoside phosphorylase, PNP, PNPase or inosine phosphorylase is an enzyme that in humans is encoded by the NP gene. It catalyzes the chemical reaction
Nucleic acid metabolism is a collective term that refers to the variety of chemical reactions by which nucleic acids are either synthesized or degraded. Nucleic acids are polymers made up of a variety of monomers called nucleotides. Nucleotide synthesis is an anabolic mechanism generally involving the chemical reaction of phosphate, pentose sugar, and a nitrogenous base. Degradation of nucleic acids is a catabolic reaction and the resulting parts of the nucleotides or nucleobases can be salvaged to recreate new nucleotides. Both synthesis and degradation reactions require multiple enzymes to facilitate the event. Defects or deficiencies in these enzymes can lead to a variety of diseases.
Ribose 5-phosphate (R5P) is both a product and an intermediate of the pentose phosphate pathway. The last step of the oxidative reactions in the pentose phosphate pathway is the production of ribulose 5-phosphate. Depending on the body's state, ribulose 5-phosphate can reversibly isomerize to ribose 5-phosphate. Ribulose 5-phosphate can alternatively undergo a series of isomerizations as well as transaldolations and transketolations that result in the production of other pentose phosphates as well as fructose 6-phosphate and glyceraldehyde 3-phosphate.
Purine metabolism refers to the metabolic pathways to synthesize and break down purines that are present in many organisms.
Ribose-phosphate diphosphokinase is an enzyme that converts ribose 5-phosphate into phosphoribosyl pyrophosphate (PRPP). It is classified under EC 2.7.6.1.
In enzymology, an AMP nucleosidase (EC 3.2.2.4) is an enzyme that catalyzes the chemical reaction
In enzymology, an inosine nucleosidase (EC 3.2.2.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a NAD+ glycohydrolase (EC 3.2.2.5) is an enzyme that catalyzes the chemical reaction
In enzymology, a ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase (EC 3.2.2.6) is a bifunctional enzyme that catalyzes the chemical reaction
In enzymology, a NMN nucleosidase (EC 3.2.2.14) is an enzyme that catalyzes the chemical reaction
In enzymology, a pyrimidine-5'-nucleotide nucleosidase (EC 3.2.2.10) is an enzyme that catalyzes the chemical reaction
In enzymology, an adenosine-phosphate deaminase (EC 3.5.4.17) is an enzyme that catalyzes the chemical reaction
In enzymology, an IMP cyclohydrolase (EC 3.5.4.10) is an enzyme that catalyzes the chemical reaction
In enzymology, a xanthine phosphoribosyltransferase is an enzyme that catalyzes the chemical reaction
Bisphosphate may refer to:
Pyridoxal 5′-phosphate synthase (glutamine hydrolysing) (EC 4.3.3.6, PdxST) is an enzyme with systematic name D-ribose 5-phosphate,D-glyceraldehyde 3-phosphate pyridoxal 5′-phosphate-lyase. This enzyme catalyses the following chemical reaction
