a relation between an independent continuant (the bearer) and a function, in which the function specifically depends on the bearer for its existence

A bearer can have many functions, and its functions can exist for different periods of time, but none of its functions can exist when the bearer does not exist. A function need not be realized at all the times that the function exists.

has function

this enzyme has function this catalysis function (more colloquially: this enzyme has this catalysis function)

http://purl.obolibrary.org/obo/obi.owl