Biochemists study the molecules that define the structure and function of living beings.
A forester will discuss the fact that it is the leaves of the tree which are green. This is beginning to get to the nitty gritty of life at a molecular level. Take a look at the c hlorophyll molecule as a biochemist would visualize it. Take a look at Michael Lynch 's work at University College, Dublin, on toxic algae. Take a look at what NASA is doing.