In this regard, some of the most significant waste products are the nitrogenous breakdown products of proteins and nucleic acids. When proteins and nucleic acids are broken apart for energy or converted to carbs or fats, enzymes remove nitrogen in __. __ is very toxic, in part because its ion, __, interferes with __. Although some animals excrete __ directly, many species expend energy to convert it to less toxic compounds prior to excretion.
- ammonia x2