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  • 厌氧和有氧呼吸

    What will you learn
    ::你会学到什么

    • The difference between aerobic and
      ::有氧与
    • Advantages of aerobic and anaerobic respiration
      ::有氧和厌氧呼吸的有利条件

    A person swimming with a scuba tank in a pool, illustrating underwater breathing.

    Why oxygen?
    ::为什么是氧气?

    Oxygen is the final electron acceptor at the end of the electron transport chain of aerobic respiration . In the absence of oxygen, only a few ATP are produced from glucose . In the presence of oxygen, many more ATP are made.
    ::氧是有氧呼吸电子运输链端端端的最后电子接收器,在没有氧气的情况下,只有少量ATP是用甘蔗糖生产的,在氧气存在的情况下,制造了更多的ATP。

    The Presence of Oxygen
    ::氧气的存在

    There are two types of : aerobic and anaerobic . One occurs in the presence of oxygen ( aerobic ), and one occurs in the absence of oxygen ( anaerobic ). Both begin with - the splitting of glucose.
    ::有两种类型:有氧和厌氧。一种是在氧(有氧)的情况下发生,一种是在缺氧(无氧)的情况下发生。这两种类型首先都是分解葡萄糖。

    Glycolysis is an anaerobic process - it does not need oxygen to proceed. This process produces a minimal amount of ATP. The and do need oxygen to proceed, and in the presence of oxygen, these processes produce much more ATP than glycolysis alone.
    ::液解是一种厌氧过程,不需要氧来进行。这一过程产生少量的ATP。在氧存在的情况下,这些过程产生更多的ATP而不是光是气解。

    Scientists think that glycolysis evolved before the other stages of cellular respiration. This is because the other stages need oxygen, whereas glycolysis does not, and there was no oxygen in Earth’s atmosphere when life first evolved about 3.5 to 4 billion years ago. Cellular respiration that proceeds without oxygen is called anaerobic respiration .
    ::科学家们认为,水解在细胞呼吸的其他阶段之前就演变了。 这是因为其他阶段需要氧,而水解则不需要氧,而地球大气中没有氧,而生命在35亿到40亿年前首次进化时,地球上没有氧。 没有氧的细胞呼吸是所谓的厌氧呼吸。

    Then, about 2 or 3 billion years ago, oxygen was gradually added to the atmosphere by early photosynthetic (cyanobacteria). After that, living things could use oxygen to break down glucose and make ATP. Today, most organisms make ATP with oxygen. They follow glycolysis with the Krebs cycle and electron transport to make more ATP than by glycolysis alone. Cellular respiration that proceeds in the presence of oxygen is called aerobic respiration .
    ::大约20亿或30亿年前,早期光合(clanobacteria)逐渐将氧添加到大气中。 之后, 生物可以使用氧来分解葡萄糖并制造ATP。 如今, 大部分生物用氧制造ATP。 它们遵循与 Krebs 循环和电子传输的透析, 而不是光通过光解来制造更多的ATP。 当氧存在时的细胞呼吸被称为有氧呼吸。

    Aerobic vs. Anaerobic Respiration: A Comparison
    ::有氧与厌氧呼吸:比较

    Aerobic respiration, which takes place in the presence of oxygen, evolved after oxygen was added to Earth’s atmosphere. This type of respiration is useful today because the atmosphere is now 21% oxygen. However, some anaerobic organisms that evolved before the atmosphere contained oxygen have survived to the present. Therefore, anaerobic respiration, which takes place without oxygen, must also have advantages.
    ::氧气在地球大气中添加了氧气之后,氧气的进化产生了有氧呼吸。 今天,这种类型的呼吸是有用的,因为大气现在是21 % 的氧气。 然而,在大气中含有氧气之前进化的一些有氧生物已经活到现在了。 因此,没有氧气的厌氧呼吸也必须有好处。

    Advantages of Aerobic Respiration
    ::有氧呼吸的有利条件

    A major advantage of aerobic respiration is the amount of energy it releases. Without oxygen, organisms can split glucose into just two molecules of pyruvate . This releases only enough energy to make two ATP molecules. With oxygen, organisms can break down glucose all the way to carbon dioxide. This releases enough energy to produce up to 38 ATP molecules. Thus, aerobic respiration releases much more energy than anaerobic respiration.
    ::有氧呼吸的一个主要优点是它释放的能量数量。没有氧,生物可以将葡萄糖分解成两个微弱分子。这只释放出足够的能量来制造两个ATP分子。有了氧,生物可以把葡萄糖分解成二氧化碳。这释放出足够的能量来产生多达38个ATP分子。因此,有氧呼吸所释放的能量比厌氧呼吸所释放的能量要多得多。

    The amount of energy produced by aerobic respiration may explain why aerobic organisms came to dominate life on Earth. It may also explain how organisms were able to become multicellular and increase in size.
    ::有氧呼吸产生的能量量可以解释有氧生物主宰地球生命的原因,也可以解释生物是如何成为多细胞体并增加体积的。

    Advantages of Anaerobic Respiration
    ::厌氧呼吸的有利条件

    One advantage of anaerobic respiration, also known as , is obvious. It lets organisms live in places where there is little or no oxygen. Such places include deep , soil , and the digestive tracts of such as humans (see the Figure ).
    ::厌氧呼吸的一个好处(又称微笑是显而易见的。它让生物体生活在氧气少或缺氧的地方。 这些地方包括深水、土壤和人类等消化道(见图 )。

    Microscopic view of E. coli bacteria, illustrating anaerobic organisms in a digestive environment.
    E. coli bacteria are anaerobic bacteria that live in the human digestive tract.

    Another advantage of anaerobic respiration is its speed. It produces ATP very quickly. For example, it lets your get the energy they need for short bursts of intense activity (see the Figure ). Aerobic respiration, on the other hand, produces ATP more slowly.
    ::厌氧呼吸的另一个优点是其速度。 它很快生成 ATP 。 例如, 它让您获得它们所需的能量 来进行短时间的密集活动(见图 ) 。 另一方面, 有氧呼吸产生ATP 的速度更慢。

    Hurdles race on a track with athletes competing in a sprint event.
    The muscles of these hurdlers need to use anaerobic respiration for energy. It gives them the energy they need for the short-term, intense activity of this sport.
    DID YOU KNOW?
    Anaerobic bacteria can grow in injured human tissues that do not have oxygen supply through due to damaged . This results in infections like tetanus and gangrene.
     

    Summary
    ::摘要

    • Cellular respiration always begins with glycolysis, which can occur either in the absence or presence of oxygen.
      ::细胞呼吸总是从凝解开始,在缺乏氧气或存在氧气的情况下可以进行凝解。
    • Cellular respiration that proceeds in the absence of oxygen is anaerobic respiration.
      ::没有氧气的细胞呼吸是厌氧呼吸
    • Cellular respiration that proceeds in the presence of oxygen is aerobic respiration.
      ::在氧气条件下继续的细胞呼吸 是有氧呼吸
    • Anaerobic respiration evolved prior to aerobic respiration.
      ::抗氧呼吸在有氧呼吸前演变而来。
    • Aerobic respiration produces much more ATP than anaerobic respiration.
      ::有氧呼吸比厌氧呼吸产生更多的ATP。
    • Anaerobic respiration occurs more quickly than aerobic respiration.
      ::有氧呼吸比有氧呼吸更快发生。

    Review
    ::回顾

    1. Define aerobic and anaerobic respiration.
      ::定义有氧和厌氧呼吸。
    2. What process is common to both aerobic and anaerobic respiration?
      ::有氧和厌氧呼吸的共同过程是什么?
    3. Why do scientists think that glycolysis evolved before the other stages of cellular respiration?
      ::为什么科学家们认为 水解会先于细胞呼吸的其他阶段呢?
    4. What is the main advantage of aerobic respiration? Of anaerobic respiration?
      ::有氧呼吸的主要好处是什么?无氧呼吸的主要好处是什么?
    5. Tanya is on the high school track team and runs the 100-meter sprint. Marissa is on the cross-country team and runs 5-kilometer races. Explain which type of respiration the muscle cells in each runner’s legs use.
      ::Tanya是高中轨道队成员,负责100米的冲刺。 Marissa是跨国家队成员,参加5公里的赛跑。 解释一下每个跑者腿上的肌肉细胞使用哪种呼吸方式。