| Oxidation of metabolic fuels is essential to life. In higher organisms, fuels, such as carbohydrates and lipids are metabolized to carbon dioxide and water. Most metabolic energy is provided by oxidation-reduction reactions in mitochondria. This is no small feat, because warm-blooded animals have such variable demands for energy from such processes as thermogenesis at low temperatures, stimulation of ATP synthesis during stress, degradation of excess food, efficient use of nutrients during starvation, and coupling of ATP synthesis with the rate of respiration. This chapter will provide an introduction to the concept of free energy, oxidative phosphorylation and the transduction of energy from fuels into useful work. The pathways and specific molecules through which electrons are transported to oxygen and the mechanism of generation of ATP will be described and related to the structure of the mitochondrion, the powerhouse of the cell and the major source of cellular ATP. Lastly, these biochemical processes will be applied to human health and disease.
|
|
