BIOL 240 Lecture Notes - Lecture 21: Homeothermy, Uncoupling Protein, Poikilotherm

• School: University of San Diego
• Department: Biology Courses
• Course: BIOL 240
• Professor: Lisa Baird

Document Summary

Mentioned various factors that contribute to evolution from poikilotherms. Need to consider an additional important change. Challenge: large temp difference between animal and environment drives rapid heat loss. The lower the temperature the more rapid the rate of loss. Solution: generate enough heat to replace what is lost. No atp made but energy is released as heat. A physiological state of decreased activity and metabolism. Adaptive hypothermia in which metabolism and body temp are lowered at night to prevent overnight starvation. Bats and hummingbirds reduce their set point every day while they are inactive. Can lower heart rate to a few beats/min. That is an adaptation to winter cold and scarce food supply. Body temp is cooled and metabolic rate may be 20 times less. Drop in metabolic rate is not a function of lower body temperature since drop precedes decline in body temperature. Studies suggest inhibition of electron transport system. Alternative oxidase involved in addition to regular pathway.