I have a set of protein sequences (specifically enzymes) found in the same organism. However, I have a doubt when defining the relationship between them. For example:

a) A set of sequences share the same composition of amino acids, but lack the active site. b) On the other hand another set of sequences differ in the composition of amino acids but contain the active site and of course the enzymatic function.

My question is could they be called protein isoforms and paralogs?