The amount of content took me by surprise for sure, and the amount of work you'll need to do outside of lessons too. And also the amount of credits you can do. In my Biochem course I could only choose 1x20 credit module(which lasts for 12 weeks) or 2x 10 credit modules ( 1 being 6 weeks long). Which kinda sucked since some of the other modules sounded quite interesting
I believe the Biologists get a lot more free reign in their chosen modules as I think they get 100 credits worth to work with. Side note, if you are doing Biology, I recommend you take the Molecular and Cell Biology module (assuming that they'll have the same structure for modules next year) so you'll have more choice for your 2nd year modules
And a bioscience friend of mine was taken by surprised about the amount of lab work/ structure of lab sessions since they're 3 hour blocks (though the amount of sessions you have a week depends on your course and chosen modules) though you can leave early if you get everything done.
I'm not really sure about contact hours, so I can't really say, but lecturers are usually up for answering your questions when they can.