Aactually the term “BIOCHEMISTRY” means the chemistry of life.
it is just like a BRIDGE between our physiological & metebolic processes and the chemical reactions going across them.
hence biochemistry is the basis for all other science fields like biotechnology, microbiology and others.
For biochemistry you should both know chem and bio. According to the subject you prefer to work on more chem than bio or more bio than chem may be needed. But this is a slight difference.
Personally, I prefer subjects that are more related than bio than chem in biochemistry.