Calorimetry and Energy Production

Energy Production and ATP

• When the body uses energy, only about 40% is utilized for work.
• The usable form of energy in the body is ATP (adenosine triphosphate).
• The remaining 60% of energy is converted to heat.

Direct Calorimetry

• Direct calorimetry is a technique used to measure the body's heat production.
• Since heat is a byproduct of energy production, measuring heat output indicates the quantity of energy produced.
• The basic unit of heat is the calorie.

Calorimetry Chamber

• A calorimetry chamber is used to measure heat production.
• It consists of an insulated, airtight chamber.
• The walls of the chamber contain tubing.
• Water is continuously circulated through the tubing to absorb the heat produced by the body inside the chamber.
• The heat produced inside the chamber is measured via the water temperature change, allowing the determination of the energy production.