临床营养学教学课件-2014讲授临床营养学课件第二节课.ppt

二、脂类(lipids) 谢惠波 2014年秋 （一）三酰甘油( triglycerides, TG) 1.功能Function (1)供能和储能（Storing and providing the body with energy）: 9.46kcal /1g (两个特点） (2)内分泌作用（ Incretion）: 分泌系列因子—leptin（瘦素）, TNF-α, IL-6, IL-8, adiponectin（脂联素）, resistin, estrogen（雌激素）, Insulin-like（胰岛素样）growth factor (IGF), angiotensinogen (血管紧张素), IGF binding protein 3, plasminogen activator inhibitor (PAI, 纤维蛋白溶酶原激活因子抑制物) (3)维持体温恒定，保护器官等。The layer of fat beneath the skin helps keep the body warm ( insulating the body). Protecting and propping up the organs in the body (1)增加饱腹感Because dietary fat causes the stomachto empty more slowly than either carbohydrate or protein, it imparts satiety and satisfaction. (2)改善食物感官Improving the color, flavor, taste and shape of foods. (3)帮助脂溶性维生素吸收 To supply body with fat-soluble vitamins and aid intestinal absorption of them. (4)供能和提供必需脂肪酸Providing body with energy and essential fatty acid. (二) 磷脂 (phospholipid) 1. Structure： 2. Function (1) 组成细胞膜 Important constituents of cell membranes. (2) 帮助脂溶性物质通过 They thus allow fat-soluble substances, including vitamins and hormones, to pass easily in or out of cells. (3) 作为乳化剂 As emulsifiers(乳化剂)in the body or food manufacturers. (4) 供能 To supply body with 9 kcalories per gram. (三) 固醇 (Sterols) 2. Classification and Function: 胆固醇 细胞结构和功能Essential to the structure and function of cells, especially the cell membrane (about 90% of total body cholesterol ). 合成体内活性物质Cholesterol is the original material for synthesis of many vitally important body compounds such as bile, sex hormones, adrenal hormone, and vitamin D. 植物固醇 常见的植物固醇有β-谷固醇、菜固醇和豆固醇。植物固醇可以干扰肠道对膳食中胆固醇和胆汁中胆固醇的吸收，因此，具有降低人和动物血清胆固醇的作用。植物固醇主要来源是植物油、种籽和坚果等食品 1. 分类Classification chain length: （链长） long-chain (10~14 carbons or more) medium-chain (6 or 8 --) short-chain ( 2—4 or 2—6) position of double bond: “n” or “ω” “n-3”和 “n-6 2. 必需脂肪酸 ( Essential fatty acid, EFA) (1)To maintain the structural parts of cell memb