<p>If the only thing you want to do is learn biochemistry, Oxford is definitely your best bet as you will cover a lot more. You can still learn a lot at an American uni, though, and you will also have the benefit of learning other disciplines. Like I said, if time isn’t an issue, you will reach the same endpoint whichever path you choose, but the American system will leave you with some more varied academic experience whilst the Oxford system will not. But if you’re itchy to get there as fast as possible, choose Oxford and don’t look back. :)</p>