Biology 2601A/B Lecture Notes - Lecture 2: Muscle Contraction, Photosynthesis, Ectotherm
26 Oct 2013
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Lecture 2: temperature i principles of thermal biology. A measure of the speed or intensity of the incessant random motions that all the atoms and molecules of any substance undergo on an atomic-molecular scale. More exactly, the temperature of a substance is proportional to the product of the mean square speed of the random molecular motions and the molecular mass (hwa, p. 227) Temperature intensity of motion by the atoms in the object. Heat amount of energy in the object. Temperature determines the direction of heat transfer (warm cool) Endotherms generate internal heat (metabolic heat) Ectotherms rely on external temperatures to determine tb (body temperature) Homeotherms defend a constant body temperature. Poikilotherms allow body temperature to vary. Heterotherms have more than one temperature set point, or switch between homeo- and poikilothermy. Relationship between temperature and metabolism in an ectotherm. Metabolic rate increases exponentially (approximately) as temperature increases.
