Question

A researcher is trying to design an experiment to measure the amount of energy a person uses during different activities. He proposes to measure heart rate as an indirect measure of metabolic rate. Which of the following would give him a more precise measure of energy use?

Comparing the amount of sugar released in the urine before and after the activity

Measuring the amount of carbon dioxide released from the lungs during the activity

Monitoring the number of calories voluntarily consumed following the activity

Tracking the increase in sweat production over the course of th

Answer 1

Metabolism or metabolic rate determines how much food an organism will require and how it is able to get it. All the options can be used to determine metabolic rates because they require breakdown of foods. In option A during activity, sugar will be consumed faster, some sugar will be released from the liver in to the blood and used by the body, the waste of which is found in urine. So, more sugar will be found in the urine after activity, which increases with the rate of activity. In option B during activity, more oxygen will be used and more carbon dioxide will be expelled, so it can be used to determine metabolic rate. In option C more calory will be used during activity and can be used to determine metabolic rate. In option D more sweat willed be produced to regulate the body temperature because more heat will be produced during activity. Also during activity more nitrogen will be used and more sweat will be produced to eliminate urea. So increase in sweat can be used to determine metabolic rates due to activity.

Answer 2

Measuring the amount of carbon dioxide released from the lungs during the activity