Pathogenic microorganisms produce toxins through different biochemical pathways. For instance, bacterial toxins can be classified into endotoxins and exotoxins. Endotoxins are part of the bacterial cell wall and are released when the cells disintegrate, while exotoxins are secreted into the surrounding environment. Viruses, on the other hand, can cause cellular damage by hijacking the host's cellular machinery to replicate themselves, leading to cell death and release of toxic substances.