Chemists, biochemists, and biologists alike debate the origins of this homochirality. The biosynthesis of cocaine has long attracted the attention of biochemists and organic chemists. Biochemists are scientists that are trained in biochemistry. Other scientists associated with HIV/AIDS denialism include biochemists David Rasnick and Harvey Bialy. Biomolecular chemistry is a major category within organic chemistry which is frequently studied by biochemists. Biochemists study chemical processes and chemical transformations in living organisms. This supported the applicability of one of two rival mechanistic postulates made by starch biochemists. Similarly, biochemists use NMR to identify proteins and other complex molecules. Biochemists study DNA, proteins and cell parts. Biochemists also prepare pharmaceutical compounds for commercial distribution. Biochemists commonly use the abbreviation "Pi" to refer to inorganic phosphate. In medicine, biochemists investigate the causes and cures of diseases. Biochemists in the field of agriculture research the interactions between herbicides with plants. In agriculture, biochemists investigate soil and fertilizers. GC was ineffective for many biochemists because of the thermal instability of the solutes.