Brianne Simonsen
Lab Section 8
4 Oct. 2005
Abstract In this experiment the oxygen consumption of a mouse in environments of varying temperatures was studied. The hypothesis behind this experiment was that more oxygen would be consumed at a lower temperature to maintain body heat. To measure the rate of oxygen consumption a mouse was given a specific amount of oxygen. The amount consumed in a specific time was measured and compared to the rates at a colder temperature. Just as expected, oxygen was consumed more rapidly at a lower temperature. This would lead to the conclusion that more oxygen is required to maintain homeostasis in a system.
Introduction
Metabolic rate is a measurement of energy used by an animal within a specific period of time. This can be measured in a number of ways: recording an animal’s heat loss with a calorimeter, determining the amount of carbon dioxide an animal produces, recording an animal’s food intake compared to the food’s chemical energy potential and the amount of waste the animal creates, and finally by measuring the amount of oxygen a test subject consumes during a given period of time1. The mouse used in the experiment is an endotherm. Endotherms use energy produced through metabolism to maintain and generate consistent body heat2. Endotherms also generally have a higher metabolic rate than ectotherms (organisms that gain heat from their surroundings) 1. Factors other than endothermic or ectothermic status also influence metabolic rate, including size and activity. Size is inversely proportional to metabolic rate. Higher metabolic rates have been found in small endothermic animals; however there is no concrete explanation for this finding1. Activity also affects metabolic rate. The longer and activity lasts the lower the maximum metabolic rate becomes. In the absence of activity an organism is said to be either at its basal metabolic rate (for
References: 1 Campbell, N. and Reece, J. Biology Seventh Edition. Pearson Education, Inc., San Francisco. 2005. pp.828-838 2 Frankel, J., et al. Principles of Biology I Laboratory Manual Fifth Edition. Pearson Custom Publishing, Boston. 2005. pp.37-42 3 Information obtained from the internet at: http://en.wikipedia.org/wiki/Homeostasis