Human Anatomy and Physiology - N. I. Fedyukovich 2003

Metabolism and Energy
Lipid Metabolism

Lipids are complex Organic compounds that include neutral fats, composed of glycerol and Fatty acids, and lipoids (such as lecithin and Cholesterol). In addition to fatty acids, lipoids contain polyhydric alcohols, phosphates, and nitrogenous compounds.

Lipids play a vital role in the body's physiological processes. Some of them (Phospholipids) form the primary component of Cell membranes or serve as a precursor for the synthesis of Steroid Hormones (cholesterol). A portion of fat is stored in adipose tissue Cells as neutral reserve fat, which accounts for 10–30% of body mass, and even more in Metabolic Disorders. The mobilization of fat to meet the body's energy demands involves the Hydrolysis of triglycerides and the release of Free energy-yielding fatty acids. From an energetic standpoint, the Oxidation of Fatty acids yields twice as much energy as Proteins and CARBOHYDRATES (1 g equals 9.3 kcal). An adult requires 70–80 g of fat daily. Fats have significance beyond mere energy supply. They dissolve and transport so-called Essential Fatty Acids (linoleic, linolenic, and arachidonic, collectively grouped as vitamin F) as well as Fat-soluble Vitamins (vitamins A, D, E, K) out of the body. Lipid METABOLISM is closely intertwined with protein and Carbohydrate Metabolism. When intake increases, proteins and carbohydrates can be converted into fats.

The Central Nervous system, along with various Endocrine glands (Gonads, Thyroid Gland, Pituitary Gland, and Adrenal Glands), plays a significant role in the Regulation of Lipid Metabolism.



Last update: 08/08/2026

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