ZOO 3210 Study Guide - Final Guide: Glutamine Synthetase, Glutamine, Exhalation

• School: University of Guelph
• Department: Zoology
• Course: ZOO 3210
• Professor: Jim Ballantyne

Document Summary

Considerations: toxicity of end products, solubility of end products. Three main nitrogen excretory products: urea, uric acid, ammonia. In the pathways to get to uric acid from ammonia, some of the intermediates chosen along the way are things like guanine, allantoin, and allantoic acid. Ammonia toxicity: crosses membranes by diffusion including blood- brain barrier, disrupts ion gradients when converted to nh4+ In brain, elevated ammonia leads to elevated glutamate which may compromise the neurotransmitter role of glutamate affecting receptors. Excretion need lots of water: ammonia tends to be excreted by aquatic organisms (elasmobranchs don"t excrete very much ammonia because they save as much of their nitrogen to make urea) Urea: elasmobranch nitrogen excretion, the kidney doesn"t excrete very much, instead has an inevitable loss at the gills happening at the surface. There is a high percentage of urea loss in the gills: characteristics of parotid saliva form the.