Biochemistry allows us to understand how various chemical processes in all living organisms interact and function to support life. It covers a wider range of scientific disciplines, which are sub-categorised into different branches. In this unit, the importance of biochemistry in medicine, health sectors, nutrition, and the living system has been discussed in detail. It also helps to understand biological phenomena of the environment and its conversation, genetic manipulations of genes via recombinant DNA technology and gene sequencing via human genome project. The knowledge of biochemistry has advanced tremendously and in forthcoming years, it has a potential role in unravelling the mystery of life processes.