• Question: Why do we get energy from oxygen???

    Asked by anon-181562 on 11 Jun 2018.
    • Photo: Lauren Burns

      Lauren Burns answered on 11 Jun 2018:

      We don’t get energy straight from oxygen, but we use the oxygen to unlock the energy that’s in the food we eat. When you breathe, your heart and lungs move all that oxygen from the air to the different cells in your body through your blood, which combine the oxygen with carbohydrates and sugars from food and “burn” it for energy. Like the engine in a car or a plane, your body needs more oxygen to do more burning, which is why we breathe so heavily when we exercise!

    • Photo: Joanne Sharpe

      Joanne Sharpe answered on 12 Jun 2018:

      Oxygen is used in aerobic respiration to release energy from glucose. Glucose is produced by breaking down the food we have eaten, and this is used with oxygen to produce ATP, which is like the currency of energy that our body uses.

    • Photo: Alex Haragan

      Alex Haragan answered on 12 Jun 2018:

      On a slightly more historical perspective:
      Life has been around on earth for roughly 4 billion years. And for 3 of those 4 it was only single-cell organisms (life forms).
      Trying to figure out the biology and history of that period is difficult, but many people are looking at it from different ways.
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      One major thing that seemed to have happened was various single-cell organisms (mostly forms of bacteria) were living and, as part of their waste process, released oxygen. Now, oxygen is actually quite a disruptive chemical – and some forms of it (like free radicals) are harmful to cells, both ours and other species. When a organism is just one cell oxygen can be fatal!
      So for millions of years oxygen was being released into the air, forming the atmosphere, but generally toxic, so the bacteria stayed in the waters and places oxygen couldn’t get.
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      Now the next step is that some species of bacteria evolved to use oxygen – and in the right way it turned out to be an excellent way of liberating energy from other chemicals, and provided loads of spare room for them to live. Oxygen was so good at this, that virtually every complex species on earth now requires oxygen in one form or another. Humans have evolved very complex mechanisms (that as stated involved ATP and the kreb’s cycle etc) – but the ultimate reason why is because of these ancient events!
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      Life always finds a way – and its worth remembering there are plenty of anaerobic bacteria (that require a non-oxygen environment to live) still living!

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