BIOL 103 Lecture Notes - Allantois, Saltwater Fish, Osmosis
22 Apr 2013
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Document Summary
Biology lecture #5 excretion and ion transport. Lecture covers nitrogenous wastes, salt and water balance as well as kidney function. Many vital processes have potential to disturb the balance between salt and water concentrations. Obligatory exchanges are necessary as part of respiration or elimination of wastes. Water and salt will be loss through body respiration, ingestion of food will be eliminated as waste (unnecessary parts) as well as through metabolism. Product of the breakdown of amino acids and nucleic acid degradation. The waste produced is species and environment dependent, such as ammonia, urea and uric acid. Most aquatic animals excrete ammonia or ammonium ions. Little energy required for prudction, high amount of water needed to excrete and has high toxicity. Most mammals, amphibians, marine fishes and terrestrial invertebrates excrete urea. Requires moderate energy and moderate amount of water for excretion, has a low toxicity. Birds, insects and most reptiles excrete uric acid.
