Tvrzická E, Stanková B, Vecka M, Zák A
Univerzita Karlova v Praze, 1. lékarská fakulta, IV. interní klinika, Praha.
Cas Lek Cesk. 2009;148(1):16-24.
Fatty acids are monocarboxylic acids with chain-length 2-36 carbon atoms and 0-6 double bonds. Their physico-chemical properties are reflected also in the compounds, where fatty acids represent an important component (phospholipids, triglycerides), as well as in higher organized structures (plasma membranes, lipoproteins). Fatty acids are synthesized from two-carbon precursors; their degradation by beta-oxidation is accompanied by energy-release. Fatty acids are classified with respect to double bonds into saturated, monounsaturated and polyunsaturated. Simple lipids are esters of fatty acids and organic alcohols - cholesterol, glycerol and sphingosine and their derivatives. Endogenous acids can be desaturated up to Delta9 position; desaturation to other position is possible only from exogenous (essential) acids [(linoleic (n-6 series) and alpha-linolenic (n-3 series)]. Circulating lipids (in form of lipoproteins) consist of cholesterol esters and triglycerides in nonpolar core and phosphatidylcholin and sphingomyelin in the polar envelope of lipoproteins. Nonesterified fatty acids (product of lipolysis and source for lipid synthesis) are bound to plasma albumin. Membrane lipids, which ensure membrane fluidity and other functions, consist of phosphatidylcholine, phosphatidylethanolamine, sphingomyelin and some other (minor) phospholipids.
脂肪酸是链长为2至36个碳原子且含有0至6个双键的单羧酸。它们的物理化学性质也体现在脂肪酸作为重要组成部分的化合物中（磷脂、甘油三酯），以及更高层次的组织结构中（质膜、脂蛋白）。脂肪酸由双碳前体合成；其通过β-氧化的降解伴随着能量释放。脂肪酸根据双键分为饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸。简单脂质是脂肪酸与有机醇（胆固醇、甘油和鞘氨醇及其衍生物）形成的酯。内源性酸可去饱和至Δ9位；只有从外源性（必需）酸（亚油酸（n-6系列）和α-亚麻酸（n-3系列））才能去饱和至其他位置。循环脂质（以脂蛋白形式）在脂蛋白的非极性核心中由胆固醇酯和甘油三酯组成，在极性包膜中由磷脂酰胆碱和鞘磷脂组成。非酯化脂肪酸（脂解产物和脂质合成的来源）与血浆白蛋白结合。确保膜流动性和其他功能的膜脂由磷脂酰胆碱、磷脂酰乙醇胺、鞘磷脂和其他一些（少量）磷脂组成。
