Section outline

  • General

    Collapse all Expand all

  • 有氧对有氧呼吸-高级

     

    Oxygen gas

    Why oxygen?
    ::为什么是氧气?

    Anaerobic vs. aerobic . Which is more efficient? It does depend on oxygen. Why do ALL your need oxygen? 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.
    ::抗氧对有氧体。 哪一种更有效率? 它取决于氧气。 为什么你需要氧气? 氧是有氧呼吸电子运输链尾端的最后电子接收器。 在缺乏氧气的情况下,只有少量ATP是用葡萄糖生产的。在有氧气的情况下,还制造了更多的ATP。

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

    As aerobes in a world of aerobic organisms , we tend to consider aerobic respiration “better” than . In some ways, it is. However, has persisted far longer on this planet, through major changes in the atmosphere and life. There must be value in this alternative way of making ATP.
    ::在一个有氧生物的世界里,我们往往认为有氧呼吸“比”有氧呼吸“更好 ” 。 在某些方面,它的确更好。 然而,由于大气和生命的重大变化,地球上的有氧呼吸持续时间更长。 以这种替代方式制作ATP必须具有价值。

    lesson content
    E. coli bacteria are anaerobic bacteria that live in the human digestive tract.

    A major argument in favor of aerobic over anaerobic respiration is overall energy production. Without oxygen, organisms can only break a 6-carbon glucose into two 3-carbon pyruvate molecules. As we saw earlier, releases only enough energy to produce two (net) ATPs per molecule of glucose. In anaerobic respiration, this is where ATP production stops. There is a final total of only two ATPs produced per molecule of glucose. This anaerobic process does occur very quickly though. For example, it lets your get the energy they need for short bursts of intense activity.
    ::赞成厌氧呼吸有氧比有氧呼吸有氧的主要论点是总体能源生产。没有氧,生物只能将六碳葡萄糖破碎成两个三碳蒸发分子。正如我们早些时候所看到的那样,只有足够的能量能生产出两种(净)乙酸甘蔗分子。在厌氧呼吸中,这是ATP生产停止的地方。最后只有两种乙酸甘蔗分子生产出ATP。尽管这种厌食过程发生得非常快。例如,它能让您获得短时间密集活动所需的能量。

    lesson content
    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.

    Aerobic respiration, on the other hand, produces ATP more slowly. It does, however, break glucose all the way down to CO 2 , producing up to 38 ATPs. Membrane transport (active transport) costs can slightly reduce this theoretical yield, but aerobic respiration consistently produces at least 15 times as much ATP as anaerobic respiration. This vast increase in energy production probably explains why aerobic organisms have come to dominate life on Earth. It may also explain how organisms were able to increase in size, adding multicellularity and great diversity.
    ::另一方面,有氧呼吸产生ATP的速度较慢。但是,它的确把葡萄糖切成CO2, 产生多达38个ATP。 氨膜运输(活性运输)成本可以略微降低这一理论产量,但有氧呼吸持续产生至少15倍于厌氧呼吸的ATP。 能源生产的巨大增长也许解释了为什么有氧生物体主宰了地球上的生命。它也可以解释生物体如何能够增加体积,增加多细胞性和巨大的多样性。

    However, anaerobic pathways do persist, and obligate anaerobes have survived over 2 billion years beyond the evolution of aerobic respiration. So there must be advantages to fermentation. What are these advantages?
    ::然而,厌氧路径的确持续存在,而且强制厌食者在氧呼吸演变后20多亿年的寿命已经超过20亿年。 因此发酵一定有好处。 这些好处是什么?

    One advantage is available to organisms occupying the few anoxic (lacking oxygen) niches remaining on earth. Oxygen remains the highly reactive, toxic gas that caused the “Oxygen Catastrophe.” Aerobic organisms have evolved a few necessary materials, namely and antioxidants , to protect themselves. Organisms living in anoxic niches do not run the risk of oxygen exposure, so they do not need to spend energy to build these elaborate chemicals.
    ::一种优势是占据地球上少数缺氧(缺氧)切片的有机体。 氧仍然是导致“氧气灾难”的高度反应性有毒气体。 有氧生物为自我保护发展了一些必要的材料,即抗氧化剂。 生活在缺氧切片中的有机体不会冒氧接触的风险,因此不需要花费能源来制造这些精密的化学物质。

    Individual cells that experience anoxic conditions face greater challenges. As demonstrated by lactic acid fermentation , muscle cells “still remember” anaerobic respiration, using this fermentation to make ATP in low-oxygen conditions, regenerating NAD + during this process. However, other cells, like brain cells do not “remember” anaerobic respiration, and consequently cannot make any ATP without oxygen. This explains why death follows for most humans who endure more than four minutes without oxygen.
    ::经历厌氧条件的个体细胞面临更大的挑战。 正如电酸发酵所证明的那样,肌肉细胞“仍然记得”厌氧呼吸,利用这种发酵在低氧条件下使ATP在低氧条件下产生ATP,在此过程中再生NAD+。然而,其他细胞,如脑细胞,并不“记得”厌氧呼吸,因此不能在没有氧的情况下产生任何ATP。这解释了为什么大多数没有氧过四分钟的人类会因此死亡。

    Variation in muscle cells gives further insight into some benefits of anaerobic respiration. In vertebrate muscles, lactic acid fermentation allows muscles to produce ATP quickly during short bursts of strenuous activity. Muscle cells specialized for this type of activity show differences in structure as well as chemistry. Red muscle fibers are “dark” because they have a rich supply for a steady supply of oxygen, and a , myoglobin, which holds extra oxygen. They also contain more , the in which the and electron transport chain conclude aerobic respiration. This is endurance muscle. White muscle cells are “light” because they lack the rich blood supply, have fewer mitochondria, and store the glycogen rather than oxygen. This is muscle built for sprinting.
    ::肌肉细胞的变异使人们更深入地了解厌氧呼吸的一些好处。在脊椎肌肉中,实验性酸发酵使肌肉能够在短短的紧张活动连发期间迅速产生ATP。专门用于这种活动的肌肉细胞在结构和化学结构上都存在差异。红肌肉纤维是“暗”的,因为它们有供氧稳定供应的丰富供应,还有含有额外氧的血红蛋白。它们还含有更多的,其中,电子运输链和电磁传输链形成有氧呼吸。这就是耐力肌肉。白肌肉细胞是“亮亮的”,因为它们缺乏丰富的血液供应,其mitochondria数量较少,并且储存基因而不是氧。这是用于打印的肌肉。

    Each type of muscle fiber has advantages and disadvantages, which reflect their differing biochemical pathways. Aerobic respiration in red muscles full of mitochondria produces a great deal of ATP from far less glucose - but slowly, over a long time. Anaerobic respiration in white muscle cells full of carbohydrates produces ATP rapidly for quick bursts of speed, but a predator who continues pursuit may eventually catch a white-muscled prey .
    ::每一种肌肉纤维都有其优点和缺点,这反映了它们不同的生化途径。 充满了米托乔因德里亚(mitochondria)的红肌肉有氧呼吸从远不那么低的葡萄糖中产生大量ATP-但缓慢,持续了很长一段时间。 充满碳水化合物的白色肌肉细胞有氧呼吸迅速产生ATP,快速地迅速爆发,但继续捕食的掠食者最终可能捕捉到一个白色的肉食。

    Summary
    ::摘要

    • Aerobic and anaerobic respiration each have advantages under specific conditions. Aerobic respiration produces far more ATP but risks exposure to oxygen toxicity. Anaerobic respiration is less energy-efficient but allows survival in habitats that lack oxygen.
      ::有氧和厌氧呼吸在特定条件下各有优势。有氧呼吸产生更多的ATP,但有暴露于氧毒性的风险。有氧呼吸的节能效率较低,但允许在缺乏氧的生境中生存。
    • Within the human body, both aerobic and anaerobic respiration are important to muscle function.
      ::在人体内,有氧和厌氧呼吸对肌肉功能很重要。
    • Muscle cells specialized for aerobic respiration provide endurance and those specialized for lactic acid fermentation support short but intense energy expenditures.
      ::专门用于有氧呼吸的肌肉细胞提供耐力,而那些专门用于实验性酸发酵的细胞则提供短但密集的能源支出支持。
    • Both ways of making ATP play critical roles in life on earth.
      ::使ATP在地球上的生命中发挥关键作用的两种方式。

    Summary
    ::摘要

    • Aerobic respiration is far more energy-efficient than anaerobic respiration.
      ::与厌氧呼吸相比,有氧呼吸的能效要高得多。
    • Aerobic processes produce up to 38 ATP per glucose.
      ::有氧过程产生最高为每根葡萄糖38ATP。
    • Anaerobic processes yield only 2 ATP per glucose.
      ::厌氧过程只产生2个ATP/每个葡萄糖。

    Review
    ::回顾

    1. 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?
    2. 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。请解释每个跑者腿上的肌肉细胞使用哪种呼吸方式。
    3. Construct a chart that compares aerobic to anaerobic fermentation in the following qualities; definition, cells that use it, amount of energy released, reactants, products, stages, and site of reactions.
      ::构造一个图表,将有氧与厌氧发酵作比较,其特性如下:定义、使用该发酵的细胞、释放的能量量、反应剂、产品、阶段和反应地点。