Metabolism Assays from BioVision. Metabolism are all biochemical processes of an organism. Cell metabolism is the process (or really the sum of many ongoing individual processes) by which living cells process nutrient molecules and maintain a living state. Cell metabolism involves extremely complex sequences of controlled chemical reactions called metabolic pathways. BioVision offers an extensive line of metabolism assay kits. Metabolites can be measured by fluorometric (Ex/Em = 535/587 nm) and colorimetric ( λ = 570 nm) methods.