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  • 碳水合物 - 高级

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    Sugar. Does this look like biological energy?
    ::糖,这看起来像生物能量吗?

    As a child, you may have been told that sugar is bad for you. Well, that's not exactly true. Essentially, carbohydrates are made of sugar, from a single sugar molecule to thousands of sugar molecules all attached together. Why? One reason is to store energy . But that does not mean you should eat it by the spoonful.
    ::小时候,你可能被告知糖对你不好。这并非完全正确。基本上,碳水化合物是用糖制成的,从一个糖分子到数千个糖分子。为什么?原因之一是储存能量。但这并不意味着你应该用勺子吃它。

    Carbohydrates
    ::碳水合物

    Carbohydrates are that contain only carbon (C), hydrogen (H), and oxygen (O). They are the most common of the four major types of organic compounds. There are thousands of different carbohydrates, but they all consist of one or more smaller units called monosaccharides .
    ::碳水化合物只含有碳(C)、氢(H)和氧(O)。它们是四种主要有机化合物中最常见的。有数千种不同的碳水化合物,但它们都包含一个或一个以上较小的单位,称为单沙焦。

    Monosaccharides and Disaccharides
    ::单数和分数

    The general formula for a monosaccharide is (CH 2 O) n , where n can be any number greater than two. For example, if n is 6, then the formula can be written C 6 H 12 O 6 . This is the formula for the monosaccharide glucose . Another monosaccharide, fructose, has the same chemical formula as glucose, but the atoms are arranged differently. Molecules with the same chemical formula but with atoms in a different arrangement are called isomers . Compare the glucose and fructose molecules in Figure . Can you identify their differences? The only differences are the positions of some of the atoms. These differences affect the properties of the two monosaccharides.
    ::单沙委的普通公式是 (CH2O)n, n 可以是大于两个的数值。 例如, 如果 n为 6, 那么公式可以写C6H12O6 。 这是单沙委的葡萄糖的公式。 另一种单沙委的公式是fructose, 与葡萄糖的化学公式相同, 但原子的排列却不同。 使用相同化学公式的分子和不同安排中的原子的分子被称为异构体。 比较图中的葡萄糖和浮糖分子。 您能够辨别它们的区别吗 ? 唯一的区别是某些原子的方位。 这些差异影响两个单沙委的特性 。

    Monosaccharides can be classified by the number of carbon atoms they contain: diose (2), triose (3), tetrose (4), pentose (5), hexose (6), heptose (7), and so on.
    ::单色化物可按其所含碳原子的数量分类:二(2)、三(3)、四(4)、钢管(5)、六(6)、七(7)等等。

    In addition to glucose, other common monosaccharides include fructose (" fruit sugar"), galactose, xylose ("wood sugar") and ribose (in RNA) and deoxyribose (in DNA).
    ::除葡萄糖外,其他常见的单核糖包括葡萄糖(Fructase )(“水果糖”),黄甘糖,Xylose (“木糖”),以及糖(RNA)和脱氧核糖核酸(DNA)。

    If two monosaccharides bond together, they form a carbohydrate called a disaccharide . Two monosaccharides will bond together through a dehydration reaction, in which a molecule is lost. A dehydration reaction is a condensation reaction , a chemical reaction in which two molecules combine to form one single molecule, losing a small molecule in the process. In the dehydration reaction, this small molecule is water. The bond between two monosaccharides is known as a glycosidic bond .
    ::如果将两个单色分解物结合在一起,它们形成一种碳水化合物,称为分离物。两种单色分解物通过脱水反应结合在一起,在脱水反应中,一个分子消失。脱水反应是一种凝聚反应,一种化学反应,在这种反应中,两个分子合并成一个单一分子,在这个过程中失去了一个小分子。在脱水反应中,这个小分子是水。两个单色分解剂之间的结合被称为液态联结。

    An example of a disaccharide is sucrose (table sugar), which consists of the monosaccharides glucose and fructose ( Figure ). Other common disaccharides include lactose ("milk sugar") and maltose. Monosaccharides and disaccharides are also called simple sugars . They provide the major source of energy to living .
    ::一种非焦酸物的例子就是sucrose(可口糖),它由单核酸甘蔗和fructose(图)组成,其他常见的不热剂包括乳糖(“牛奶糖”)和麦芽糖。单核酸和不可口酸也被称为简单的糖。它们提供了生活的主要能量来源。

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    Sucrose Molecule. This sucrose molecule is a disaccharide. It is made up of two monosaccharides: glucose on the left and fructose on the right. Sucrose forms through a condensation reaction: glucose (C 6 H 12 O 6 ) + fructose (C 6 H 12 O 6 ) sucrose (C 12 H 22 O 11 ).
    ::sucrose 分子 。 此sucrose 分子是一种分解体。 它由两种单细胞组成: 左边的葡萄糖和右边的纤维糖。 苏crose 形成时会通过凝结反应: 葡萄糖 (C6H12O6) + fructose (C6H12O6) sucrose (C12H22O11)。

    Oligosaccharides
    ::奥利戈塞层

    An oligosaccharide is a saccharide polymer containing a small number (typically two to ten) of monosaccharides. Oligosaccharides can have many functions; for example, they are commonly found on the plasma membrane of cells where they can play a role in cell–cell recognition. In general, they are found attached to compatible amino acid side-chains in or to .
    ::寡叶沙丁酸是一种含有少量(通常为2至10个)单胞胎的沙焦化聚合物。 奥利戈沙焦可以有许多功能;例如,它们通常在细胞的血浆膜上找到,可以在细胞识别中发挥作用。 一般来说,它们被附着在相容的氨基酸边链上,或附在细胞识别中。

    Oligosaccharides are often found as a component of glycoproteins or glycolipids. They are often used as chemical markers on the outside of cells, often for cell recognition. An example is ABO blood type specificity. A and B have two different oligosaccharide glycolipids embedded in the of the red blood cells , AB-type has both, while O blood type has neither.
    ::Oligosaccharides经常被发现是甘蓝蛋白或甘蓝脂的组成部分,通常在细胞外部用作化学标记,通常用于细胞识别,例如ABO血型特性。A和B在红血细胞中存在两种不同的寡醇酸甘蓝脂,AB型两种都有,O型血型两种都没有。

    Polysaccharides
    ::复数

    Polysaccharides are long carbohydrate molecules of repeated monomer units joined together by glycosidic bonds. A polysaccharide may contain anywhere from a few monosaccharides to several thousand monosaccharides. Polysaccharides are also called complex carbohydrates . Polysaccharides have a general formula of C x (H2O) y , where x is usually a large number between 200 and 2500. Considering that the repeating units in the polymer backbone are often six-carbon monosaccharides, the general formula can also be represented as (C 6 H 10 O 5 ) n , where 40≤n≤3000.
    ::多元碳酸盐是一种长碳水化合物分子,由多单体单体单位组成,并配以晶体联结。多元碳酸盐可能含有从几个单体相到几千个单体相之间的任何地方。多元碳酸盐也称为复杂的碳水化合物。多体碳酸盐具有一种一般的碳(H2O)y配方,其中x通常在200至2500之间,而x通常在200至2500之间。考虑到聚合骨的重复单位往往是六碳单体。一般公式也可以以(C6H10O5n,其中40°n3000)表示。

    Starches are one of the more common polysaccharides. Starch is made up of a mixture of amylose (15–20%) and amylopectin (80–85%). Amylose consists of a linear chain of several hundred glucose molecules and amylopectin is a branched molecule made of several thousand glucose units. Starches can be digested by hydrolysis reactions , catalyzed by called amylases , which can break the glycosidic bonds. Humans and other animals have amylases, so they can digest starches. Potato, rice, wheat, and maize are major sources of starch in the human diet. The formations of starches are the ways that plants store glucose. Glycogen is sometimes referred to as animal starch. Glycogen is used for long-term energy storage in animal cells. Glycogen is made primarily by the liver and the .
    ::恒星是更为常见的聚变植物之一。 恒星是由灭蚁灵( 15- 20% ) 和 ammyopectin( 80- 85% ) 的混合物构成的。 Amyloess 是由几百 个葡萄糖分子组成的线性链条和 ammyopectin 由数千 个葡萄糖单位组成的分支分子组成。 恒星可以通过水解反应消化, 被叫做 ammylass( ammylass) 的催化作用, 它可以打破藻类联系。 人类和其他动物有粒子, 从而可以消化恒星。 土、 大米、小麦和玉米是人类饮食中淀粉的主要来源。 恒星的形成是植物储存葡萄糖的方式。 凝胶有时被称为动物恒星体。 甘素被用于动物细胞的长期能量储存。 甘醇主要由肝和肝脏组成。

    The main functions of polysaccharides are to store energy and form structural tissues . Examples of several other polysaccharides and their roles are listed in Table . These complex carbohydrates play important roles in living organisms .
    ::聚碳化合物的主要功能是储存能量和形成结构组织,其他几个聚碳化合物及其作用的例子列于表。 这些复杂的碳水化合物在活生物体中起着重要作用。

    Complex Carbohydrates
    Complex Carbohydrate Function Organism
    Starch Stores energy

    Plants
    ::工厂 工厂

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    Amylose Stores energy Plants
    Glycogen Stores energy

    Animals
    ::动物动物

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    Cellulose Forms cell walls

    Plants
    ::工厂 工厂

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    Chitin Forms an exoskeleton

    Some animals
    ::一些动物

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    KQED: Biofuels: From Sugar to Energy
    ::KQED: 生物燃料:从糖到能源

    For years there's been buzz – both positive and negative – about generating ethanol fuel from corn. But thanks to recent developments, the Bay Area of California is rapidly becoming a world center for the next generation of green fuel alternatives. The Joint BioEnergy Institute is developing methods to isolate biofuels from the sugars in cellulose. 
    ::多年来,人们 — — 不管是正的还是负的 — — 都在抱怨从玉米中产生乙醇燃料。 但是,由于最近的事态发展,加利福尼亚湾地区正迅速成为下一代绿色燃料替代品的世界中心。 联合生物能源研究所正在开发将生物燃料从纤维素糖中分离出来的方法。

      

     

    Summary
    ::摘要

    • Carbohydrates are organic molecules that consist of carbon, hydrogen, and oxygen.
      ::碳水化合物是由碳、氢和氧组成的有机分子。
    • Carbohydrates are made up of repeating units called saccharides.
      ::碳水化合物由重复的单位组成,称为沙焦化物。
    • Carbohydrates provide cells with energy, store energy, and form structural tissues.
      ::碳水化合物为细胞提供能量、储存能量和形成结构组织。

    Review
    ::回顾

    1. What are carbohydrates?
      ::什么是碳水化合物?
    2. State the function of monosaccharides, such as glucose and fructose.
      ::葡萄糖和软糖等单亚酸盐的功能。
    3. Compare and contrast simple sugars and complex carbohydrates.
      ::比较和对比简单的糖和复杂的碳水化合物。
    4. What are glycoproteins and glycolipids?
      ::什么是甘蓝蛋白和甘蓝?
    5. Give examples of polysaccharides.
      ::举例来说,有聚亚焦量。