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Lipids
Lipids are a diverse group of biomolecules that are primarily characterized by their insolubility in water and solubility in organic solvents. They serve essential functions in living organisms, including energy storage, insulation, protection, and as structural components of cell membranes. Lipids are composed of carbon, hydrogen, and oxygen atoms, but they have a higher proportion of carbon and hydrogen compared to oxygen, giving them their hydrophobic nature. Below are examples of lipids .
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Fatty Acids: Fatty acids are the building blocks of many lipids. They are long hydrocarbon chains with a carboxyl group (COOH) at one end. Fatty acids can be either saturated (no double bonds between carbon atoms) or unsaturated (one or more double bonds between carbon atoms). They can vary in chain length and degree of saturation, leading to different properties and functions.
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Triglycerides: Triglycerides, also known as triacylglycerols, are the most common type of dietary fat and the primary storage form of energy in animals. They consist of three fatty acids esterified to a glycerol molecule. Triglycerides serve as a concentrated source of energy and insulation in the body.
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Phospholipids: Phospholipids are a major component of cell membranes. They consist of a glycerol molecule esterified to two fatty acids and a phosphate group. Phospholipids have a hydrophilic (water-loving) head and hydrophobic (water-repelling) tails, which gives them amphipathic properties. This allows them to form lipid bilayers in cell membranes, creating a barrier that separates the cell from its surroundings.
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Steroids: Steroids are lipids with a specific four-ring structure. They serve various functions in the body, including hormone regulation, cell signaling, and as components of cell membranes. Examples of steroids include cholesterol, which is an important component of cell membranes, and hormones such as estrogen, testosterone, and cortisol.
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Waxes: Waxes are long-chain fatty acids esterified to long-chain alcohols. They are water-repellent and serve as protective coatings on the surfaces of plants, animals, and some insects. Waxes provide a waterproof barrier, preventing excessive water loss and protecting against environmental factors.