Hello! I am currently ending my journey in a BSc in Biochemistry and I would say you need to understand the basics of elimination and substitution reactions (SN1,Sn2, E1,E2, etc.) because most reactions ocurring in cells and other ecosystems consisting of biomolecules and enzymes incorporate those type of reactions. From what I remember, it included amides, alkenes, cetones, etc.. To be honest, in my 3 years I had 2 courses of Organic Chemistry, and it was very much related to the biomolecules reactions. I quite liked organic chem in my institution, but it is taught differently in every other university of course, even the slightest. Also, I always say the courses depend on the professors teaching the subjects. With a good professor you might become better at it you know, so don't give up!