6.16 酶
章节大纲
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An cleaner like the one pictured here contains called enzymes. The enzymes attach themselves to particular stains and help break them down. Different enzymes work on different types of stains, such as grease stains or bloodstains. Removing stains isn’t the only use of enzymes. Enzymes are also essential to life.
::像这里所描绘的清洁者一样,清洁者含有被称为酶的酶。 酶附着在特定的污点上,并帮助将其破碎。 不同的酶对不同种类的污点(如油脂或血迹)进行工作。 去除污点并非是酶的唯一用途。 酶也是生命的关键。Why Living Things Need Enzymes
::生活为何需要酶constantly occur inside the cells of living things. However, under the conditions inside cells, most would occur too slowly to maintain life. That’s where enzymes come in. Enzymes are in living things. Like other catalysts, they up chemical reactions. Enzymes are proteins that are synthesized in the cells that need them, based on instructions encoded in the cells’ DNA.
::然而,在细胞内部的条件下,大部分都发生得太慢,无法维持生命。这就是酶进入的地方。酶存在于生物中。同其它催化剂一样,它们也会产生化学反应。 酶是需要它们的细胞中合成的蛋白质,根据细胞DNA编码的指示。How Enzymes Work
::酶如何工作Enzymes increase the rate of chemical reactions by reducing the amount of needed for reactants to start reacting. One way this can happen is modeled in the Figure . 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. Each enzyme is highly specific for the particular reaction is catalyzes, so enzymes are very effective. A reaction that would take many 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.
::酶通过减少反应者开始反应所需的反应量来增加化学反应速度。 一种可以发生这种情况的方式是图中的模型。 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。 每种酶对于特定反应来说都是非常具体的是催化,因此酶非常有效。 一种需要多年时间而没有酶的反应可能会在与酶分立的秒内发生。 酶也非常有效,因此废物产品很少形成。Q: This model of enzyme action is called the lock-and-key model. Explain why.
::Q: 这种酶动作模式被称为锁键模式。 请解释原因 。A: The substrates (reactants) fit precisely into the active site of the enzyme like a key into a lock. Being brought together in the enzyme in this way helps the reactants react more easily. After the product is formed, it is released by the enzyme. The enzyme is now ready to pick up more reactants and catalyze another reaction.
::A: 子元素( 活性剂) 精确地与酶的活性位置相匹配, 就像锁中的钥匙一样。 以这种方式在酶中聚集在一起, 有助于反应者更容易反应。 产品形成后, 由酶释放。 酶现在可以接收更多的反应剂, 并催化另一种反应 。Digestive Enzymes
::活性酶More than 1000 different enzymes are necessary for human life. Many enzymes are needed for the digestion of food. Two examples are amylase and pepsin. Both are described in the Figure .
::人类生命需要1000多种不同的酶,食物消化需要许多酶,二例为氨基酶和。Summary
::摘要-
Enzymes are catalysts in living things. They speed up biochemical reactions.
::酶是活物的催化剂 它们加速生化反应 -
Under the conditions inside living cells, biochemical reactions would occur too slowly to support life without the help of enzymes.
::在生物细胞内的条件下,生化反应会发生太慢,无法在没有酶帮助的情况下维持生命。 -
Enzymes increase the rate of biochemical reactions by reducing the amount of activation energy needed for reactants to start reacting.
::酶通过减少反应器开始反应所需的激活能量量,提高生化反应的速度。 -
More than 1000 different enzymes are necessary for human life, and many help digest food. Two examples are amylase and pepsin.
::人类生命需要1000多种不同的酶,许多酶帮助消化食物。 甲酰酶和素就是两个例子。
Review
::回顾-
What are enzymes?
::什么是酶? -
Why are enzymes needed to catalyze chemical reactions in living things?
::为什么需要酶来催化活体中的化学反应? -
How do enzymes speed up biochemical reactions?
::酶如何加速生化反应? -
Describe two human digestive enzymes.
::描述两种人类消化酶。
Explore More
::探索更多Watch the video about enzymes and then answer the questions below.
::观看关于酶的视频,然后回答下面的问题。-
In the video, the presenter uses a pair of scissors as an analogy for an enzyme. Identify the active site of the scissors enzyme, its substrate, and the chemical reaction it catalyzes.
::在影片中,主讲人用一把剪刀作为酶的类比。 确定剪刀酶的活性地点、其基底以及它催化的化学反应。 -
What is the induced fit theory? How does it differ from the lock-and-key model described above?
::诱导的合身理论是什么?它与上述锁和钥匙模式有何不同? -
Identify two factors that affect how well an enzyme works.
::查明影响酶工作良好程度的两个因素。
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Enzymes are catalysts in living things. They speed up biochemical reactions.
