BIOB34H3 Chapter Notes - Chapter 10: Homeothermy, Osmosis, Thermoregulation
Document Summary
Membrane phospholipid restructuring is a chronic response to temperature change over a few days or more. Supercooling: the ability of an aqueous solution to remain unfrozen below freezing temperatures. It is an unstable state and will eventually freeze spontaneously at its supercooling point. Intracellular freezing can be fatal for animals; however they are tolerant of the freezing of extracellular fluids. When freezing occurs in animals, it starts w/ extracellular fluids. This basically means that extracellular freezing is self limiting, there is only so much fluid that can freeze before the solute concentration in the remaining fluid becomes to high to allow freezing. Water stops leaving the cell when the cell"s os(cid:373) p(cid:396)essu(cid:396)e e(cid:395)uals that of the extracellular fluid. Poikilotherms can behaviorally avoid freezing conditions (e. g. stick to bottom of the lake during winter) Physiological tolerance of freezing: production of antifreeze compounds. Solutions containing these antifreezes exhibit thermal hysteresis, where their freezing point is much lower than their melting point.
