what do you mean by biochemistry ?

Biochemistry:

It is fundamentally the utilization of chemistry principles to the study of biological processes at the cellular & molecular level. Biochemistry is the chemistry of living organisms and the molecular basis for the changes occurring in living cells- thus it is both life science and chemical science. Rules of physics, chemistry, molecular biology, and immunology are being used to study the structure and behavior of the complex molecules found in biological material and also their ways of molecular interactions to form cells, tissues, and whole organisms.

Biochemistry, in other words, is tied in with learning the bits of knowledge of the concoction responses that make, break, run, and fix the parts that make up our body.