What are exotoxins?

Exotoxins are indeed proteins that are secreted by bacteria into the surrounding environment. These proteins are often highly toxic and can cause significant harm to host organisms by disrupting cellular processes, damaging tissues, or triggering extreme immune responses. They are produced by both Gram-positive and Gram-negative bacteria and can act at a distance from the site of infection, which allows them to have systemic effects.

The other choices refer to different concepts. Byproducts of bacterial metabolism are typically not secreted proteins but rather waste products that may not have any toxic effects. Genetic materials within bacteria refer to DNA or RNA, which are essential for bacterial reproduction and function but are not involved in the toxic manifestations that exotoxins elicit. Lastly, metabolites found in soil do not pertain to bacterial exotoxins and describe compounds that may be of microbial or environmental origin but not specifically toxic proteins released by bacteria.