Answer:
Cholesterol
Step-by-step explanation:
Cholesterol is the main sterol of the human body. Sterols are a type of natural fat present in the body. Cholesterol is found in our body as part of cell membranes, lipoproteins, bile acids and steroid hormones.
Cholesterol, contrary to its popular image as a powerful enemy of health and longevity, is actually a crucial substance that performs countless vital functions for the organism. Cholesterol is essential for animal life because of its numerous functions:
- Structural: cholesterol is a very important component of the plasma membranes of animals (in general, it does not exist in vegetables). Although cholesterol is found in small amounts in cell membranes, in the cytoplasmic membrane we find it in a 1: 1 molar ratio relative to phospholipids, regulating their physicochemical properties, in particular fluidity. However, cholesterol is found in a very low proportion or is practically absent in subcellular membranes.
- Precursor of vitamin D: essential in calcium metabolism.
- Precursor of sex hormones: progesterone, estrogen and testosterone.
- Precursor of corticosteroid hormones: cortisol and aldosterone.
- Precursor of bile salts: essential in the absorption of some lipid nutrients and * main route for excretion of body cholesterol.
- Precursor of lipid rafts.