Is it ok to ask my biochem 1 and biochem 2 prof. for LOR? Please help

I was just wondering if it's ok to get LOR from a biochem 1 and a biochem 2 professor. The reason why I asked is b/c I am a biology major, but I closer to these two professors and so wondering if it's gonna look weird since it's both from biochem. And also does anyone know who the letter should be addressed to? I mean like, Dear Admission committee, or to whomever it may concern b/c my dentist is writing me LOR but this is her first time doing this and so she asked me and I don't know. Anyway, thanks