A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction
Any of the cell-surface glycoproteins that are encoded by genes of the major histocompatibility complex and that are involved in the regulation of immune responses.
Any extracellular or intracellular molecule (e.g. a hormone, neurotransmitter, second messenger, etc.), released in response to a stimulus that promotes a particular reaction in a cell, or behaviour in an organism; especially such a molecule involved in cell-to-cell communication.
= cell adhesion molecule.
An aggregation of atomic nuclei or subatomic particles.
(In the terminology of Buffon) any of the minute indivisible particles of which living things are constituted and by means of which they reproduce (now historical).
Any of various proteins present on the surface of a cell which mediate its attachment to other cells or to a substrate; abbreviated CAM.
Any of a group of cell adhesion molecules that mediate the establishment and maintenance of contacts between neurons, neurites and their supporting and target cells; abbreviated NCAM.
A molecule that is involved in the maintenance and metabolic processes of living organisms
The quantity of a chemical compound equal to its molecular weight in grams; now usually replaced by the mole. Also called gram molecule