Comparing the BMR of Mice and Humans

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Summary The respiratory system is responsible in regulating gas exchange between the body and the external environment. Differences in respiration rate indirectly influence basal metabolic rate (BMR) by providing the necessary components for adenosine triphosphate (ATP) formation (Williams et al., 2011). Observation of gas exchange were measured and recorded for two mice (mus musculus) weighing 25 g and 27 g under the conditions of room temperature, cold temperature (8°C), and room temperature after fasting using a volumeter. The rates of oxygen consumption and carbon dioxide production were measured and used to calculate BMR, respiratory quotient (RQ) and oxidation rate. The mouse at room temperature was calculated to have a BMR of 2361.6 mm3/g/hr. Under conditions of cold temperature and fasting, the BMR values decreased to 2246.4 mm3/g/hr and 2053.2 mm3/g/hr respectively. Rates of glucose oxidation increased under these treatments while rates of fat oxidation decreased. Respiratory quotient (RQ) values were calculated to determine the fuel source for metabolic activity. On a relative scale, protein or fat appeared to be the primary fuel source for all three treatments although the mouse at 8°C had the highest RQ and may have relatively used the most glucose. It was also concluded that BMR in mice are greater than in humans. Introduction In this experiment mice were studied as examples of organisms that employ physiological mechanisms to maintain and regulate internal body temperature. The respirometer uses the principle of water displacement. As the amount of gas in the respirometer changes, this will be reflected by an equivalent displacement of water in the pipette. Remember that at the same temperature and pressure,... ... middle of paper ... ...ted trends and are likely affected by many other factors such as illnesses, the presence of humans, or different external environments. Works Cited Akin, J. A. (2011) Homeostatic Processes for Thermoregulation. Nature Education Knowledge.3, 7. Biology 2A03 Lab 4 Respiratory Gas Exchange in a Mouse Lab Manual. Winter Term 2014 (2014). Biology Department. McMaster University. Gordon, C. J. (2012) The mouse: an “average” homeotherm. J Ther Bio.37, 286-290. Minke, B. and Maximilian, P. (2011) Rhodopsin as Thermosensor? Science.331, 1272-1273. Williams, C. T., Goropashnaya, A. V., Buck, C. L., Fedorov, V. B., Kohl, F., Lee, T. N., and Barnes, B. M. (2011). Hibernating above the permafrost: effects of ambient temperature and season on expression of metabolic genes in liver and brown adipose tissue of arctic ground squirrels. J Experi Biol. 214, 1300-1306.
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