Phytochemistry is the study of chemicals derived from plants. Phytochemists isolate and extract compounds from plants to define their structures and test their functions in vitro and in plant and human biology. The three major groups of phytochemicals are polyphenols like flavonoids and phenolic acids, terpenoids like carotenoids, and thiols like glucosinolates. Students seeking help with phytochemistry assignments can contact experts at MyAssignment Services.