Hey! Im in fourth year biochem, and I took both those courses in my third year. They're great courses, as material from those courses literally pops up in almost EVERY course that I take.
Second year in biochem was my hardest year. Taking organic chemistry at the same time as Biochem 2L06 and physical chemistry was tough for me that first term, and I don't think I could have handled kin at the same time. It isn't one of those, study just before the midterm kinda courses, you had to keep up with the material for the tests every week. Personally, I don't think I would have had as much time as I would have liked to study for Kin in 2nd year. Third year biochem however, was my easiest year and I really got a chance to enjoy the kin anatomy courses all year.
If your thinking of going into biochem, I highly recommend taking these kin courses in third year. I had to keep trying solar for quite a few days to get into them, but it was totally worth it! Don't feel like you've missed out, you still have 3 years to take those courses
Also, I don't recommend taking the courses in the summer at another school if it is online... it really isn't the same. What makes the McMaster Kin Anatomy courses really good are 1) the amazing profs that teach them (Parise & MacDonald), and 2) the great labs.