140 likes | 1.27k Views
Nitrogen Excretion. Nitrogen excretion is necessary due to amino acid breakdown. Ammonia. Excreted as NH 3 or NH 4 + NH 3 passively diffuses NH 4 + needs transporters Most fish, simple invertebrates, molluscs, sharks (live in water) Expends little energy. Uric Acid. Highly concentrated
E N D
Nitrogen Excretion Nitrogen excretion is necessary due to amino acid breakdown
Ammonia • Excreted as NH3 or NH4+ • NH3 passively diffuses • NH4+ needs transporters • Most fish, simple invertebrates, molluscs, sharks (live in water) • Expends little energy
Uric Acid • Highly concentrated • Requires energy to produce • Less toxic than ammonia • Birds, reptiles, insects
Urea • Less toxic than ammonia • Much energy needed to produce it • Made in liver, released into bloodstream, excreted primarily in kidney • All mammals, some bony fish
Variations • Lungfish can convert from ammonia excretion to urea excretion depending on surroundings (water vs. air)