I studied first and second year biology at university about 15 years ago, taking courses in cell biology, comparative physiology, microbiology, and human cell biology. I also took the supporting courses in organic chemistry, but I have never taken a formal biochemistry class.
Recently, a family member developed a rare cancer and we have been reading through journal papers in nutrition and medicine while trying to understand how diet plays a role. These make extensive reference to specific metabolic pathways in human cells -- some I am familiar with, but many which I am not. In all cases though, my cursory education in the pathways of metabolism and cell function feels inadequate.
So, what are some comprehensive biochemistry texts that can be used as a reference for reading papers in the nutritional and medical sciences?
I would prefer not to use a "concepts" book as one might find in a light version of a course. I am not a shy reader and am not daunted by the prospect of using a more comprehensive book as a learning vehicle, nor of having to do further backtracking to the world of organic chemistry when I encounter a class of molecules that deserves attention.
Lastly, I'm on a bit of a budget too. If you know of a book with a long lineage that is likely to be offered cheaply in previous editions, it would be of tremendous value.