6.13 生化反应
Section outline
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This marathon runner has just finished running a 26.2-mile race! Running that far nonstop takes a lot of energy—you can tell how drained she is from her face. But you don’t have to run a marathon to use . All living things need energy all the time just to stay alive. Whether it’s running a marathon or simply taking a breath, energy is required. Where does all that energy come from? The answer is .
::这个马拉松赛跑者刚刚完成了一场262英里的赛跑!跑这么远的不停跑需要很多精力——你可以分辨出她的脸有多疲惫。但是你不必跑马拉松才能使用。所有生物都需要精力才能生存下去。不管它跑马拉松还是呼吸,都需要能量。所有能量都来自哪里?答案是:Chemical Reactions in Living Things
::活物中的化学反应Chemical reactions that take place inside living things are called biochemical reactions ( bio- means “life”). It’s not just for energy that living things depend on biochemical reactions. Every function and structure of a living organism depends on thousands of biochemical reactions taking place in each cell. The sum of all these biochemical reactions is called metabolism.
::生物体中发生的化学反应被称为生化反应(生物-生物-指“生命 ” ) 。 生命体依赖生化反应的不仅仅是能量。 生物体的每一个功能和结构都取决于每个细胞中发生的成千上万的生化反应。 所有这些生化反应的总和被称为新陈代谢。Catabolic and Anabolic Reactions
::代代和代谢反应Biochemical reactions of metabolism can be divided into two general categories: catabolic reactions and anabolic reactions.
::新陈代谢的生物化学反应可分为两大类:新陈代谢反应和新陈代谢反应。-
Catabolic reactions involve breaking bonds. Larger molecules are broken down to smaller ones. For example, complex
are broken down to simple sugars. Catabolic reactions release energy, so they are exothermic.
::离子反应涉及到断裂键。 大分子被细分为小分子。 例如,复杂分子被细分为简单的糖。 离子反应释放能量,因此它们具有异温性。 -
Anabolic reactions involve forming bonds. Smaller molecules are combined to form larger ones. For example, simple sugars are combined to form complex carbohydrates. Anabolic reactions require energy, so they are endothermic.
::新陈代谢反应涉及形成联结。 较小的分子被组合成较大的分子。 比如,简单的糖被组合成复杂的碳水化合物。 新陈代谢反应需要能量,因此它们是内温。
Q: Imagine! Each of the trillions of cells in your body is continuously performing thousands of catabolic and anabolic reactions. That’s an amazing number of biochemical reactions—far more than the number of reactions that might take place in a lab or factory. How can so many biochemical reactions take place simultaneously in our cells?
::问题:想象一下!你身体中的每几万亿个细胞都在不断进行成千上万的代谢和新陈代谢反应。 这是数量惊人的生化反应 — — 比实验室或工厂中可能发生的反应数量还要多得多。 我们的细胞中怎么能同时发生这么多生化反应呢?A: So many reactions can occur because biochemical reactions are amazingly fast.
::A:许多反应都可能发生, 因为生化反应速度惊人之快。Q: In a lab or factory, reactants can be heated to very high temperatures or placed under great pressure so they will react very quickly. These ways of speeding up chemical reactions can’t occur inside the delicate cells of living things. So how do cells up biochemical reactions?
::问题:在实验室或工厂中,反应器可以被加热到极高的温度,或者承受巨大的压力,这样它们就能很快地作出反应。这些加速化学反应的方法不可能发生在生命的微妙细胞中。 那么细胞如何产生生化反应呢?A: The answer is .
::答:答案是:The Importance of Enzymes
::酶的重要性Enzymes are that increase the rate of chemical reactions by reducing the amount of needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cell’s DNA. Enzymes aren’t changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form.
::酶是指通过降低反应剂开始反应所需的反应量来增加化学反应率。 酶根据细胞DNA编码的指示,在需要反应的细胞中合成。 酶没有改变,也没有在它们催化的反应中被使用,因此它们可以被用来一次又一次地加速同样的反应。 酶对于某些化学反应非常特殊,因此非常有效。 需要多年才发生而没有酶的反应可能与酶隔开一秒就发生。 酶也非常有效,因此废物产品很少形成。Photosynthesis and Cellular Respiration
::光合成和细胞呼吸Some of the most important biochemical reactions are the reactions involved in and . Together, these two processes provide energy to almost all of Earth’s organisms. The two processes are closely related, as you can see in the Figure . In photosynthesis, light energy from the sun is converted to stored chemical energy in glucose. In cellular respiration, stored energy is released from glucose and stored in smaller amounts that cells can use.
::一些最重要的生化反应是其中涉及的反应和。这两个过程共同为几乎所有的地球生物提供能量。正如图所示,这两个过程是密切相关的。在光合作用中,太阳的光能被转换为葡萄糖中的储存化学能量。在细胞呼吸中,储存的能量从葡萄糖中释放出来,并储存在细胞可以使用的较小数量。Q: What are the in photosynthesis and cellular respiration?
::问题:光合作用和细胞呼吸中是什么?A: In photosynthesis, carbon dioxide (CO 2 ) and water (H 2 O) are the reactants. They combine using energy from light to produce oxygen (O 2 ) and glucose (C 6 H 12 O 6 ). Oxygen and glucose, in turn, are the reactants in cellular respiration. They combine to produce carbon dioxide, water, and energy.
::A:在光合作用中,二氧化碳(CO2)和水(H2O)是反应剂。它们结合使用光能产生氧气(O2)和葡萄糖(C6H12O6)。氧和葡萄糖(C6H12O6)是细胞呼吸中的反应剂。它们结合产生二氧化碳、水和能源。Summary
::摘要-
Biochemical reactions are chemical reactions that take place inside living things. Thousands of biochemical reactions continuously take place inside each cell. The sum of all these biochemical reactions is called metabolism.
::生物化学反应是生命中发生的化学反应。 千千个生物化学反应在每细胞中持续发生。 所有这些生物化学反应的总和被称为新陈代谢。 -
Biochemical reactions of metabolism can be divided into two general categories: catabolic reactions, which break bonds and release energy, and anabolic reactions, which form bonds and absorb energy.
::新陈代谢的生物化学反应可分为两大类:新陈代谢反应,它打破联结并释放能量;新陈代谢反应,它们形成联结并吸收能量。 -
Enzymes are proteins that greatly increase the rate of biochemical reactions, allowing thousands of reactions to occur simultaneously in living cells.
::酶是蛋白质,大大提高了生化反应的速度,使数千种反应同时在活细胞中发生。 -
The chemical reactions of photosynthesis and cellular respiration together provide energy to virtually all living things on Earth.
::光合作用和细胞呼吸的化学反应共同为地球上几乎所有生物提供能量。
Review
::回顾-
What is a biochemical reaction?
::什么是生化反应? -
Compare and contrast catabolic and anabolic reactions.
::比较和对比代谢和新陈代谢反应。 -
Why are enzymes needed for biochemical reactions?
::为什么生物化学反应需要酶? -
How are photosynthesis and cellular respiration related?
::光合作用和细胞呼吸如何相关?
Explore More
::探索更多Watch the video about metabolism and then answer the questions below.
::观看关于新陈代谢的视频,然后回答下面的问题。-
How is metabolism defined in the video?
::视频中如何定义新陈代谢? -
Fill in the blanks in the following sentences with the terms that follow.
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The harvesting of energy is __________.
::收获的能量是_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ -
The using of energy is __________.
::能源的使用是_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ -
Organisms who get energy themselves are __________.
::自己获得能量的生物体是 。 -
Organisms who get energy from other sources are __________.
::从其他来源获得能源的生物体是__________________________________________________________________________________________________________________________________________________________________________________________________ -
Using sunlight to make organic matter is __________.
::利用阳光制造有机物是_____________________________________________。 -
Using inorganic molecules to make organic matter is __________.
::使用无机分子制造有机物是 。
::在下面的句子中填满空白。 能量的收获是 。 能量的使用是 。 获得能量的有机体本身就是 。 从其他来源获得能量的有机体是 。 利用阳光制造有机物是 。 利用无机分子制造有机物是 。 -
The harvesting of energy is __________.
anabolism autotrophs catabolism chemosynthesis heterotrophs photosynthesis -
Catabolic reactions involve breaking bonds. Larger molecules are broken down to smaller ones. For example, complex
are broken down to simple sugars. Catabolic reactions release energy, so they are exothermic.
