it may depend on the professor. i've heard of professors that were all about memorization, whereas, my biochem professor was all about concepts. as engineers, you've probably had to have honed your problem solving skills to a greater degree than your average premed and you're probably more used to thinking things out from first principles (learning is just more efficient that way). so, with the more conceptual professor, engineers will probably do fine, whereas with the hard-core memorization course, engineers will likely want to go kill themselves 🙂