Question

How are the proteins used for active transport different from those used for facilitated diffusion?

Answer 1

In facilitated diffusion, channels are just 'tubes' lined on the inside with specific amino acids for a given type of ion. e.g. negatively charged amino acids for cation transport.

Those for active transport have mechanisms/parts to hydrolyze ATP as well as crevices where ions bind to before being transported across a membrane. These aren't just 'tubes' but more complicated machines that have 'open' and 'closed' conformations.