Final answer:
The study of phytochemicals' antimicrobial and antioxidant activities is referred to as pharmacological investigations, which are linked to the field of biochemistry as well.
Step-by-step explanation:
The investigations involved in examining the antimicrobial and antioxidant activities of phytochemicals are referred to as pharmacological investigations. These investigations aim to understand how these chemicals protect human health by potentially acting as antioxidants that combat cancer-causing free radicals, and how they may be used in the development of new drugs such as antimicrobials. Current research utilizes technologies like high-throughput screening and combinatorial chemistry to expedite these studies. Moreover, the field of biochemistry often plays a significant role in understanding the metabolic pathways and effects of phytochemicals on living organisms.