ZOO 3700 Lecture Notes - Lecture 7: Mollusca, Sipuncula, Hemoglobin
20 Oct 2014
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Document Summary
Forms of nitrogenous waste secreted by various taxa. Convergence - our heart is divided into two chambers, similar to how squids have two hearts. In sea stars, small cilia create the current in the water vascular system. Hemoglobin - red (because of fe coordination within a protein), free/corpuscular, all major groups. Hemocyanin - blue/green, cu, free, mollusks, arthropods. Chlorocruorin - green, fe, free, sessile marine polychaetes. Hemerythrin - colorless/pink, fe, corpuscular, sipuncula, brachiopods. Oxygen binding curves high af nity = better at obtaining oxygen low af nity = better at giving up oxygen. In large organisms, transport of nutrients from gut not possible via diffusion alone. In hexapods, myriapods, this is the main function of circulation. In mollusks, the hepatopancreas is analogous to the vertebrate liver. Excretion of nitrogenous wastes carried out in specialized structures. Source of nitrogenous wastes from catabolism of proteins. Present in all major invert groups except cnidaria and echinodermata.
