9508628 Berner Organisms generate heat by the breakdown of fuels during cellular metabolism. In endotherms, metabolic heat can be produced fast enough to raise body temperature significantly above that of the surroundings. In ectotherms, rates of metabolic heat production are so low that body temperature is determined primarily by the surrounding environment. The aim of this research is to determine the mechanisms that permit endotherms to produce heat at a greater rate than can ectotherms. High rates of metabolic heat production are usually linked to high rates of oxygen consumption and production of usable chemical potential energy. These last two processes occur in subcellular organelles, the mitochondria. This research will contrast the rate of oxygen consumption and chemical potential energy (ATP) production by the mitochondria of endotherms and ectotherms under a variety of conditions. Experimental treatments will include varying the temperature at which the mitochondria work and varying the fuels provided to the mitochondria as they perform their metabolic functions. The research will improve understanding of the mechanisms responsible for metabolic differences between endotherms and ectotherms and of how these differences evolved.
