One can't separate the two branches of science i.e., biology and chemistry. Though chemistry deals with the study of nature, composition and properties atoms/chemicals and the interaction between them, knowledge of the field is necessary for deeper and clearer understading of the biological processes (complicated chemical reactions!).
It's for our convinience, we have them as two branches but they are higly interconnected when it comes to research, complementing each other. This has given rise to the intriguing fields of biochemistry, chemical biology, biotechnology, etc.
Chemistry, though deals with non-living world of chemical-stuff, has its applications in the living (bio) systems and is greatly needed to understand the biological processes.
A good example is that amino acids are molecules in bio-systems, yet they have a chemical structure and have chemical properties where chemistry plays its role.