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  • 三甘烯酸酯

    Close-up of golden omega-3 capsules, emphasizing the focus on dietary supplements.

    Eat right or take a supplement?
    ::吃对了还是吃补充餐?

    There is a lot of interest these days on healthy diets and as well as concerns about heart problems. There is also a strong market for the sales of omega-3 fatty acids, which are said to help lower fat levels in blood. But too many people rely on the supplements to help their hearts and don’t understand the chemistry behind it all. Yes, taking omega-3 fatty acids will give you some of the fatty acids your body requires. No, this is not a substitute for eating a healthy diet and exercising. You can’t sit in front of the TV set, eating your large pizza, and expect these pills to keep you healthy. You’ve got to do things the hard way – eat your vegetables and get some exercise. Yes, mother.
    ::这些天人们对健康饮食和心脏问题非常感兴趣。 销售奥米加-3脂肪酸的市场也很大,据说这有助于降低血液中的脂肪含量。 但太多人依赖补充剂来帮助他们的心脏,而不了解其背后的化学成分。 是的,服用奥米加-3脂肪酸会给你身体需要的一些脂肪酸。 不,这不能替代健康饮食和锻炼。 你不能坐在电视机前,吃你的大披萨,期望这些药片能保持你的健康。你必须做艰难的事情 — — 吃你的蔬菜,做一些锻炼。 是的,妈妈。

    Triglycerides
    ::三甘烯酸酯

    A is a member of a class of water-insoluble compounds that includes oils, fats, and . Oils and fats are based on the same general structure, but fats are solids at room temperature , while oils are . Butter is an example of a fat and is derived from animals. Some oils include olive oil and canola oil, which are obtained from plants. Lipids are an essential part of a healthy diet, though excess dietary fat can be harmful. Lipids store energy in the body and are also needed to keep cell membranes healthy.
    ::一种包括油、脂肪和.油和脂肪的一类水溶性化合物,其中包括油、脂肪和.油和脂肪,其结构相同,但脂肪在室温下是固体,油是固体,油是。黄油是脂肪的一个例子,是动物的产物。一些油包括橄榄油和油菜油,这些油是从植物中获取的。利皮是健康饮食的重要组成部分,尽管过量的食用脂肪可能有害。利皮将能量储存在身体中,并且还需要保持细胞膜的健康。

    One type of lipid is called a triglyceride , an ester derived from glycerol combined with three fatty molecules.  Glycerol is a triol, an which contains three hydroxyl functional groups . A fatty acid is a long carbon chain, generally from 12 to 24 carbons in length, with an attached carboxyl group. Each of the three fatty acid molecules undergoes an esterification with one of the hydroxyl groups of the glycerol molecule. The result is a large triester molecule referred to as a triglyceride.
    ::一种脂类称为三甘菊酯,一种从甘油醇与三个脂肪分子结合产生的酯。甘油醇是一种三醇,含有三个氢氧基功能组。脂肪酸是一种长碳链,一般为12至24碳,长于12至24碳,附着一个碳箱基组。三种脂肪酸分子中的每一种都经过一种甘油分子的氢氧基组的酯化。其结果是一种称为三甘油的大型试验分子。

    Chemical structure of a triglyceride, detailing its glycerol and fatty acid components.
    Triglyceride components

    Triglycerides function as a long-term storage form of energy in the human body. Because of the long carbon chains, triglycerides are nearly nonpolar molecules and thus do not dissolve readily in polar solvents such as water. Instead, oils and fats are soluble in nonpolar organic solvents such as hexane and .
    ::由于长的碳链,三甘酸盐几乎是非极分子,因此不会在水等极溶剂中轻易溶解。相反,油和脂肪在六溴和六溴等非极有机溶剂中是可溶解的。

    Fats may be either saturated or unsaturated. A saturated fat is a fat that consists of triglycerides whose carbon chains consist entirely of carbon-carbon single bonds. Therefore, the carbon chains are saturated with the maximum number of hydrogen atoms possible. An unsaturated fat is a fat that consists of triglycerides whose carbon chains contain one or more carbon-carbon double bonds . A fat with one double bond is called monounsaturated, while a fat with multiple double bonds is called polyunsaturated (see Figure ). 
    ::饱和脂肪是一种脂肪,由三甘酸酯组成,其碳链完全由碳-碳单一债券组成。因此,碳链与最大氢原子数相饱和。不饱和脂肪是一种脂肪,由三甘酸酯组成,其碳链包含一个或多个碳-碳双倍债券。一个双份债券的脂肪被称为单饱和,而一个多倍债券的脂肪则称为多元饱和(见图)。

    Structures of saturated and unsaturated triglycerides showing carbon chain bonding differences.
    Saturated and unsaturated fatty acids

    Unsaturated fat is generally considered to be healthier. High consumption of saturated fats is linked to an increased risk of cardiovascular disease. Some examples of foods with high of saturated fats include butter, cheese, lard, and some fatty meats. Foods with higher concentrations of unsaturated fats include nuts, avocado, and vegetable oils such as canola oil and olive oil. Figure  shows the percentages of fat types in some common foods.
    ::不饱和脂肪一般被认为更健康,饱和脂肪的高消费与心血管疾病风险增加有关,饱和脂肪高的一些食物例子包括黄油、奶酪、油脂和一些脂肪肉类,不饱和脂肪含量较高的食物包括坚果、鳄梨和植物油,如甘蓝油和橄榄油,图显示了某些常见食品中脂肪种类的百分比。

    Pie charts showing fat composition of various foods: saturated, monounsaturated, and polyunsaturated fats.
    Some common foods and oils along with their percentages of saturated, monounsaturated, and polyunsaturated fats.

    Review
    ::回顾

    1. What is a fatty acid?
      ::什么是脂肪酸?
    2. What is a triglyceride?
      ::什么是三重赛车?
    3. Why are unsaturated fatty acids considered healthier than saturated?
      ::为什么认为不饱和脂肪酸比饱和更健康?