For me, I took physics I, Org I, gen bio3, and two other 3 credit classes one semester, and physics 2, org 2, genetics, and two 3 credit classes the next one. I had no problem with it.
But it depends on how much YOU can handle given your available time and ability... If you're worried about adcoms thinking you didn't have a large enough course load, don't worry... it looks fine, and is very do-able.