ABSTRACT
Much of the adenosine triphosphate (ATP) produced in the mitochondria by the electron transport array of enzymes and cytochromes, the final common catabolic pathway for the oxidation of nutrients, is consumed by the anabolic pathways during biosynthesis. The major anabolic processes that consume ATP energy are the synthesis of glucose and glycogen, gluconeogenesis and glycogenesis, respectively; the synthesis of fatty acids and triglycerides; and the synthesis of the nucleic acids, deoxyribonucleic acid and ribonucleic acid, and proteins. Excess nutrient energy intake above and beyond energy requirements is converted to and stored mainly as triglyceride in depot fat. Triglycerides are formed from dietary fatty acids, fats and oils, or from dietary carbohydrates and protein via the cytoplasmic synthesis of fatty acids which are esterified with glycerol within adipose tissue. To a large degree, the synthesis and storage of triglycerides are controlled by the levels of circulating hormones, particularly insulin.
