A Question About Ability Power

If yall wanna leave now, I'm not talking about itemization.

Anyways, when I was first playing League I went AP Pantheon because he was a champion that relied on abilities, and AP said that it increases the amount of damage your abilities do. This was before I learned about scaling and such. But my question is... If I have 150 AP and my q scales off of AD, do I get 150 damage added onto whatever my ability does with the base damage and AD scaling? I know it sounds like a stupid question and I've been playing this game for like 3 years but it's just something that's always bugged me. Like AD is always used in your auto attacks regardless, so AP is used in your abilities regardless, right?