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  • 能量承载分子 - 高级

     

    lesson content

    When do you need lots of energy?
    ::你什么时候需要很多能量?

    To run a marathon, probably. Where does this extra energy come from? Remember that energy from the sun is transformed into the glucose . Carbohydrate loading is a strategy used by endurance athletes to maximize the storage of energy, in the form of glycogen, in the . Glycogen forms an energy reserve that can be quickly mobilized to meet a sudden need for glucose, which is then turned into ATP through the process of .
    ::可能是为了跑马拉松。 这个额外的能量来自哪里? 记住太阳的能量会变成葡萄糖。 碳水化合物装载是耐力运动员用来最大限度地储存能量的一种策略, 其形式是甘烃。 甘烃构成一种能量储备,可以迅速调动起来满足对葡萄糖的突然需求,然后通过过程转变为ATP。

    Food and Other Energy-Carrying Molecules
    ::食品和其他能源

    You know that the chicken you had for lunch contained molecules. But do you know that the atoms in those proteins could easily have formed the color in a dragonfly's eye, the heart of a flea, and the whiplike tail of a Euglena before they hit your plate as sleek muscle? Food consists of organic (carbon-containing) molecules which store energy in the chemical bonds between their atoms. Organisms use the atoms of food molecules to build larger organic molecules including proteins, , and fats, and use the energy in food to power life processes. By breaking the bonds in food molecules, release energy to build new compounds. Although some energy dissipates as heat at each energy transfer, much of it is stored in the newly made molecules. Chemical bonds in organic molecules are a reservoir of the energy used to make them. Fueled by the energy from food molecules, cells can combine and recombine the elements of life to form thousands of different molecules. Both the energy (despite some loss) and the materials (despite being reorganized) pass from to consumer – perhaps from algal tails, to water flea hearts, to dragonfly eye colors, to fish muscle, to you!
    ::您知道午餐时的鸡鸡含有分子。 但是,您知道,这些蛋白质中的原子可以很容易地形成眼的颜色、跳蚤的心脏和乌格伦娜的鞭子尾巴的颜色吗?食物由有机(含碳)分子组成,将能量储存在原子之间的化学联系中。有机分子利用食物分子的原子来制造更大的有机分子,包括蛋白质、脂肪和脂肪,并利用食物中的能量来制造生命过程。通过打破食物分子的纽带,释放能量来制造新的化合物。尽管一些能量在每次能量转移时都随着热量而消散,但大部分都储存在新造的分子中。有机分子中的化学联系是用来制造这些能量的能量库。由食物分子的能量、细胞可以将生命元素组合起来并重新吸收成数千种不同的分子。能源(减少一些损失)和材料(正在重新组合的)从食物分子中释放能量,释放能量,释放能量,释放能量以制造新的化合物。尽管一些能量在每次能量转移能量时,能量会随着热量的转移,但大部分储存在新的分子中。 有机分子是用来制造能量的分子的分子的分子。从食物的分子,也许从呼吸到螺,从血管到螺,到螺,从血管,到螺,从血管,到螺,到螺,到螺,到螺。

    The process of , which usually begins the flow of energy through life, uses many different kinds of energy-carrying molecules to transform sunlight energy into chemical energy and build food.
    ::通常开始能量通过生命流动的过程 利用多种不同的能量分子 将阳光能量转化为化学能量 制造食物

    Chlorophyll and NADPH
    ::氯仿和NADPH

    Some carrier molecules hold energy briefly, quickly shifting it like a hot potato to other molecules. This strategy allows energy to be released in small, controlled amounts. An example is chlorophyll , the green pigment present in most plants which absorbs solar energy and helps convert that energy into chemical energy. When a chlorophyll molecule absorbs light energy, electrons are excited and “jump” to a higher energy level. The excited electrons then bounce to a series of carrier molecules, losing a small amount of energy at each step. Most of the “lost” energy powers some small cellular task, such as moving ions across a membrane or building up another molecule. Another short-term energy carrier important to photosynthesis, NADPH , holds chemical energy a bit longer but soon that energy is used to help to build sugar. NADPH is the reduced form of NADP + , Nicotinamide adenine dinucleotide phosphate. NADP + accepts an electron at the end of the electron transport chain of photosynthesis. Two related short term energy carriers, NADH (nicotinamide adenine dinucleotide) and FADH 2 (flavin adenine dinucleotide) are used during cellular respiration .
    ::一些载体分子掌握着短暂的能量,迅速将其像热土豆一样迅速转移到其他分子中。 这个战略允许能量以小量的控制量释放出来。 一个例子是叶绿素, 叶绿素是吸收太阳能并帮助将这种能源转换为化学能源的大多数植物中存在的绿色色素。 当叶绿素分子吸收光能时, 电子就会兴奋, 并“ 跳” 进入更高的能量水平。 兴奋电子随后弹到一系列载体分子中, 每一步都会损失少量能量。 大多数“ 丢失” 能量能够让一些小细胞任务释放出来, 比如移动离子过膜或建立另一个分子。 另一种对光合作关系很重要的短期能源载体, NADPH 拥有了稍长一点的化学能量, 但很快, 能源被用来帮助建造糖。 NADP+ 的减少形式, 硝基硫化胺一种二核酸磷酸。 NADP+ 在光合作电子运输链的尽尾端接受电。 两个相关的短期能量载体, NADH (核二核基) 和二核动力二氧化的二氧化二氧化硫化二氧化硫酸。

    Glucose and ATP
    ::甘甘糖和ATP

    Two of the most important energy-carrying molecules are glucose and ATP ( adenosine triphosphate ). These are nearly universal fuels throughout the living world and both are also key players in photosynthesis.
    ::两种最重要的能量载体分子是葡萄糖和ATP(亚丁酸三磷酸),它们几乎是整个生物世界的普及燃料,两者也是光合作用的主要作用者。

    A molecule of glucose, which has the chemical formula C 6 H 12 O 6 , carries a packet of chemical energy just the right size for transport and uptake by cells. In your body, glucose is the “deliverable” form of energy, carried in your through capillaries to each of your roughly 100 trillion cells. Glucose is also the carbohydrate produced by photosynthesis, and as such is the near-universal food for life.
    ::葡萄糖分子,其化学公式为C6H12O6, 含有一包化学能量,只是细胞运输和吸收的合适尺寸。 在你的身体里,葡萄糖是“可实现的”能量形式,通过胶囊携带到你大约100万亿个细胞中的每一个细胞。 葡萄糖也是光合作用产生的碳水化合物,因此是生命的近乎普遍的食物。

    ATP molecules store smaller quantities of energy, but each releases just the right amount to actually do work within a cell. Muscle cell proteins, for example, pull each other with the energy released when bonds in ATP break open (discussed below). The process of photosynthesis also makes and uses ATP - for energy to build glucose. ATP, then, is the useable form of energy for your cells.
    ::ATP分子储存的能量较少,但每种分子释放的能量都正好相当于在细胞中实际工作。例如,肌肉细胞蛋白质在ATP断裂开关时释放的能量相互拉动(下面讨论)。光合作用的过程也产生并使用ATP来制造葡萄糖。ATP是细胞的可用能量形式。

    lesson content
    Glucose, C6H12O6, is the energy-rich product of photosynthesis, a universal food for life. It is also a six-carbon monosaccharide, or simple sugar. Glucose is the primary form in which your bloodstream delivers energy to every cell in your body, where it is converted into ATP. The six carbons are numbered.

    Why do we need both glucose and ATP? Why don't plants just make ATP and be done with it? If energy were money, ATP would be a quarter. Enough money to operate a parking meter or washing machine. Glucose would be a dollar bill (or $10) – much easier to carry around in your wallet, but too large to do the actual work of paying for parking or washing. Just as we find several denominations of money useful, organisms need several “denominations” of energy – a smaller quantity for work within cells, and a larger quantity for stable storage, transport, and delivery to cells.
    ::为什么我们既需要葡萄糖,也需要ATP? 为什么植物不做ATP呢? 如果能源是钱,ATP就是四分之一。 足够的钱可以操作停车表或洗衣机。 Glucose会是一个美元钞票(或10美元 ) — —在你的钱包里携带起来容易得多,但太大到无法实际支付停车费或洗衣费。 正如我们发现好几种货币都有用,生物体需要几种“能量集中 ” — —细胞内工作需要更少的数量,而稳定储存、运输和送入细胞需要更多数量。

    Let's take a closer look at a molecule of ATP. Although it carries less energy than glucose, its structure is more complex. “A” in ATP refers to the majority of the molecule – adenosine – a combination of a nitrogenous base and a five-carbon sugar. “T” and “P” indicate the three phosphates, linked by bonds which hold the energy actually used by cells. Usually, only the outermost bond breaks to release or spend energy for cellular work.
    ::让我们仔细看看ATP的分子。尽管它携带的能量比葡萄糖要少,但其结构则更为复杂。 ATP中的“A”是指大部分分子 — — 腺素 — — 一种氮基和五碳糖的组合。 “T”和“P”表示三种磷酸盐,这三种磷酸盐由持有细胞实际使用的能量的债券联系在一起。 通常,只有最外层的连接中断才能释放或将能量用于细胞工作。

    An ATP molecule, shown in  Figure , is like a rechargeable battery: its energy can be used by the cell when it breaks apart into ADP (adenosine diphosphate) and phosphate, and then the “worn-out battery” ADP can be recharged using new energy to attach a new phosphate and rebuild ATP. The materials are recyclable, but recall that energy is not! ADP can be further reduced to AMP (adenosine monophosphate and phosphate, releasing additional energy. As with ADT "recharged" to ATP, AMP can be recharged to ADP.
    ::图中显示的ATP分子就像一个可再充电电池:电池在分裂成ADP(乙酰二磷酸酯)和磷酸酯时可以使用其能量;然后,“废弃电池”可以用新能量补充新的磷酸盐并重建ATP。材料可以回收,但记得能量不是!ADP可以进一步减少到AMP(乙酰单磷酸酯和磷酸酯,释放额外的能量)。ADT“重新充电”ATP,AMP也可以再充电给ADP。

    How much energy does it cost to do your body's work? A single cell uses about 10 million ATP molecules per second, and recycles all of its ATP molecules about every 20-30 seconds.
    ::做你身体的工作需要多少能量?一个单细胞每秒使用大约1,000万ATP分子,每20-30秒回收其所有ATP分子。

    lesson content
    An arrow shows the bond between two phosphate groups in an ATP molecule. When this bond breaks, its chemical energy can do cellular work. The resulting ADP molecule is recycled when new energy attaches another phosphate, rebuilding ATP.

    Keep these energy-carrying molecules in mind as we look more carefully at the process which originally captures the energy to build them: photosynthesis. Recall that it provides nearly all of the food (energy and materials) for life. Actually, as you will see, we are indebted to photosynthesis for even more than just the energy and building blocks for life.
    ::当我们更仔细地观察最初捕捉能量来制造这些能量分子的过程:光合作用。回顾它几乎提供了生命所需的所有食物(能源和材料 ) 。 事实上,正如你们将看到的那样,我们感激光合作用不仅仅是生命的能量和构件。

    Summary
    ::摘要

    • All organisms use similar energy-carrying molecules for food and to carry out life processes.
      ::所有生物都使用类似的含有能量的分子作为食物,并进行生命过程。
    • Glucose (C 6 H 12 O 6 ,) is a nearly universal fuel delivered to cells, and the primary product of photosynthesis.
      ::甘蔗(C6H12O6)是几乎普及的燃料,输送到细胞中,是光合作用的主要产品。
    • ATP molecules store smaller amounts of energy and are used within cells to do work.
      ::ATP分子储存的能量较少,在细胞内用于工作。
    • Chlorophyll and NADPH molecules hold energy temporarily during the process of photosynthesis.
      ::在光合作用过程中,叶绿素和NADPH分子暂时拥有能量。

    Review
    ::回顾

    1. The fact that all organisms use similar energy-carrying molecules shows one aspect of the grand "Unity of Life." Name two universal energy-carrying molecules, and explain why most organisms need both carriers rather than just one.
      ::所有生物都使用类似的含有能量的分子,这一事实显示了“生命团结”的大目标的一个方面。 说出两个通用的含有能量的分子,并解释为什么大多数生物都需要两个载体,而不仅仅是一个载体。
    2. A single cell may use millions of ATP molecules each second. Explain how cells use the energy and recycle the materials in ATP.
      ::单细胞每秒可使用数百万个ATP分子。 请解释电池如何使用能量, 并在 ATP 中回收材料 。
    3. How many ATP molecules does a single cell use per second?
      ::单细胞每秒使用多少个 ATP 分子?
    4. Describe NADPH, NADH, and FADH 2 .
      ::描述NADPH、NADH和FADH2。