Leave out "nonfunctional" and you've got a more or less true statement.
catalys
they speed up chemical reactions
It is the opposite of narrow substrate specificity. Broad substrate specific reactions are 'less-picky' in their selection of co-chemical-reactants.
Yes, a catalyst can be re-used, because It is NOT actually used in a chemical reaction. A catalyst will increase the rate of reaction by attracting reactants, but the catalyst is not a reactant. However, the reuse cannot be done indefinitely then, depending on the severity of the reaction conditions, it can be occur a small, but accumulative deactivation of the catalys.