The United Nations often cites that a 70kg person requires approximately 2.000 kcal for simple existence, such as eating and sitting in a chair (Americans consume 3,800 kcal almost double their need). About 61% of all the energy in the foods we eat becomes heat during the formation of the energy-carrying molecule adenosine triphosphate (ATP). Still, more energy becomes heat as it is transferred to the functional systems of the cells. The functioning of the cells releases still more energy so that ultimately, all the energy released by the metabolic process eventually becomes heat. Some of this heat is used to maintain the body at an average temperature of 37C. What fraction of the 2,000 kcal is used to maintain the body temperature at 37C if the room temperature is 20C? Assume the specific heat of a human is 3.47 kJ/kg x K. Hint: When a non-phase change process occurs without a change in pressure, a change in enthalpy AH is defined as: AH = MC, AT Where AH = enthalpy change M- Mass Cp = specific heat at constant pressure AT = temperature change