The breakdown into simpler components of a vitamin, one of a number of unrelated organic substances that occur in many foods in small amounts and that are necessary in trace amounts for the normal metabolic functioning of the body.

The chemical reactions involving a nucleobase, a nitrogenous base that is a constituent of a nucleic acid, e.g. the purines: adenine, guanine, hypoxanthine, xanthine and the pyrimidines: cytosine, uracil, thymine.

The formation from simpler components of purine bases, one of the two classes of nitrogen-containing ring compounds found in DNA and RNA, which include adenine and guanine.

The chemical reactions involving a nucleoside, a nucleobase linked to either beta-D-ribofuranose (ribonucleoside) or 2-deoxy-beta-D-ribofuranose, (a deoxyribonucleotide), e.g. adenosine, guanosine, inosine, cytidine, uridine and deoxyadenosine, deoxyguanosine, deoxycytidine and thymidine (= deoxythymidine).

The chemical reactions involving a nucleotide, a nucleoside that is esterified with (ortho)phosphate or an oligophosphate at any hydroxyl group on the glycose moiety; may be mono-, di- or triphosphate; this definition includes cyclic-nucleotides (nucleoside cyclic phosphates).

modification of host morphology or physiology

The process by which an organism effects a change in the structure or function of its host organism. The host is defined as the larger of the organisms involved in a symbiotic interaction.

Any process that modulates the frequency, rate or extent of the chemical reactions involving nucleosides.

A process by which an organism has a negative effect on the functioning of the host's cells. The host is defined as the larger of the organisms involved in a symbiotic interaction.

The chemical reactions involving any ribonucleoside, a nucleoside in which purine or pyrimidine base is linked to a ribose (beta-D-ribofuranose) molecule.

dissemination or transmission of organism from host

The movement of an organism from a host to another host or from a host to another place in the environment. The host is defined as the larger of the organisms involved in a symbiotic interaction.