BIO203H5 Chapter Notes - Chapter 42: Electrochemical Gradient, Osmotic Shock, Hemolymph
Document Summary
The chemical reactions that make life possible occur in an aqueous solution. If the balance of water and solutes in the solution is disturbed, those chemical reactions and life itself may stop: an electrolyte is a compound that dissociates into ions when dissolved in water. The concentration of dissolved substances in a solution, measured in moles per liter, is referred to as its osmolarity: diffusion and osmosis affect animals differently in marine, freshwater, and terrestrial habitats. As a result, these environments pose different challenges to animals in maintaining water and electrolyte balance: osmotic stress occurs when the concentration of dissolved substances in a cell or tissue is abnormal. In contrast to osmoconformers, most marine fish are osmoregulators. Land animals also lose water when they produce urine, sweat, or pant. Land animals constantly lose water to the environment, just as many marine animals do, but they lose it by evaporation rather than osmosis.
