Biochemistry, Heat and Calories

Excerpt

Humans are endotherms, animals that keep their body temperature within a stable range using heat production and heat dissipation. The ability to produce heat from calories is an essential mechanism required for life-sustaining cellular reactions that need a sufficient intake of calories. The molecules in food contain energy, or calories, stored in chemical bonds. Metabolic reactions can extract energy from these chemical bonds and use them to power various metabolic reactions that maintain the body's homeostasis. Energy metabolism is a highly regulated process to meet the energy demands of our body under variable conditions at rest and during work or exercise.