I will be 30 next week and had to retake a few of my freshman courses, since not all schools would accept them. I would call and check with the schools themselves though, because some said I was fine and some didn't. Hope it helps.
they might be too old but that might not be such a bad thing. i remember you started a thread a few days ago asking about LORs. if you have to retake your science classes, you can get to know the professors and get some LORs.