BIOL BC 1500x Lecture Notes - Lecture 9: Thermoregulation
26 Sep 2016
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Document Summary
Metabolism equation: food + o2 => atp + nutrients + co2 + nitrogenous wastes + heat. Resting metabolic rate: rate of metabolism required for the animal to keep processes running to keep animal alive, measured by o2 consumed / unit time (vo2) If it is not thermoregulating, increase in environmental temperature -> increase in body temperature -> increase in metabolic rate (vo2) Endotherms: heat comes from metabolic processes burning food. Lose heat to environment, external temperature increases -> vo2 decreases. Being an endotherm is expensive: with endotherms metabolism of endotherms is 6-10 times higher than that of ectotherms (if they are the same size) even more expensive for very small endotherms. Surface area and volume: as animals get bigger, surface area : volume ratio gets smaller. Smaller endotherms have higher surface area : volume, lose heat faster than larger endotherms. Small ectotherms take in heat faster than larger ectotherms.
