存储和多糖的结构

描述

最普遍的一种多糖碳水化合物的饮食,也称为polycarbohydrates。他们是长链高分子碳水化合物组成的糖苷连接连接单糖单位。使用淀粉酶酶作为催化剂,这糖碳水化合物可以与水反应释放它的组件。他们有各种各样的形状直接分支。例子包括结构性多糖如纤维素和甲壳素等存储多糖淀粉、糖原和galactogen。有时很多样化,重复单元中可以看到多糖变化。这些大分子的特征可以从这些不同的单糖建设单位根据结构。他们甚至可能是水不溶性或非晶态。Homopolysaccharides或homoglycans多糖,只包含一种单糖,杂多糖或杂聚糖多糖含有多种类型的单糖。

而低聚糖包括三到十个单糖单元和多糖超过十个,完全根据公约截止略有不同。在生物,他们通常会提供一个结构或存储的目的。植物利用淀粉、葡萄糖的聚合物作为一种存储。它可以发现在形式的直链淀粉和支链淀粉。高度支化糖原越多,有时被称为“动物淀粉”是物理等效葡萄糖聚合物中发现的哺乳动物。因为它的特点、糖原可能更快地吸收,适合移动动物的积极的生活方式。他们在细菌细菌多细胞至关重要。两个结构性多糖是纤维素和甲壳素的例子。相信纤维素是地球上最常见的有机分子,用于植物的细胞壁和其他动物。它有各种各样的目的,本文中扮演了重要角色和纺织工业作为原料在赛璐珞的创建,人造丝,醋酸纤维素和硝基甲壳素也有类似的结构,但它也含有氮侧分支,从而增加其强度。 It is also found in arthropod exoskeletons and some fungi cell walls. It can also be used for a variety of things, such surgical threads. Callose or laminarin, chrysolaminarin, xylan, arabinoxylan, mannan, fucoidan and galactomannan are other polysaccharides. Nutrition. Energy comes from polysaccharides often. Most organisms cannot metabolise cellulose or other polysaccharides like cellulose, chitin or arabinoxylans, although many organisms can easily convert starches into glucose. Some bacteria and protists are capable of metabolising these forms of carbohydrates. Microorganisms for instance are used by termites and ruminants to breakdown cellulose. Although these complex polysaccharides are difficult for humans to digest, they nonetheless contain vital nutrients. These carbohydrates, known as dietary fiber, improve digestion in addition to other advantages. Dietary fiber's key effects include altering the composition of the gastrointestinal tract's contents and the way that other nutrients and substances are absorbed. In the small intestine, soluble fiber binds to bile acids to prevent them from entering the bloodstream, which decreases blood cholesterol levels. Additionally, soluble fibre slows down the absorption of sugar, lessens the spike in blood sugar that occurs after eating, normalizes blood lipid levels and after fermenting in the colon, generates short-chain fatty acids as a byproduct with a variety of physiological functions. Although insoluble fiber is linked to a lower risk of developing diabetes, it is unclear how this happens.

支链淀粉是一种支链分子几千个葡萄糖单位组成的,而直链淀粉是一个线性的几百个葡萄糖分子链。动物和人类都有淀粉酶,这允许他们消化淀粉。淀粉的主要来源,一般人的饮食是土豆,大米、小麦和玉米。植物的方式储存葡萄糖是通过淀粉的生产。动物和真菌细胞储存长期能源形式的糖原,脂肪组织作为主要的能源储备。肝脏和肌肉的主要器官产生糖原,虽然大脑和胃也可以通过一个过程称为糖原生成生产它。糖原与淀粉、植物的葡萄糖聚合物,有时被称为动物淀粉。它有一个支链淀粉的结构类似,但比淀粉更多人口分支和球状。(14)糖苷联系的聚合物(16)与分支糖原。许多不同的细胞类型包括糖原颗粒,它存在于胞质和胞浆对葡萄糖循环至关重要。 Compared to triglycerides, glycogen is less compact and more readily available as an energy store, but it can be quickly mobilized to fulfil a sudden need for glucose. Soon after a meal, glycogen can make up to 8% of the fresh weight in the liver hepatocytes. Other organs can only access the glycogen that is kept in the liver. One to two percent of the muscle mass is made up of glycogen, which is present in the muscles in low concentrations. The body's ability to store glycogen changes depending on physical activity, basal metabolic rate and feeding patterns such intermittent fasting. This is notably true for the muscles, liver and red blood cells. The kidneys and some types of brain glial cells as well as white blood cells both contain modest quantities of glycogen. During pregnancy, the uterus also stores glycogen to feed the developing foetus.