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Does eating decrease the entropy of my body?

  1. Feb 23, 2014 #1
    Hello,

    Do living beings use food to decrease the entropy of his body?

    If so, could anyone explain the process of how we do it? (or at least name a couple of keywords that I can search)

    Thank you very much.
     
  2. jcsd
  3. Feb 23, 2014 #2

    SteamKing

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    No, living things eat to keep from starving to death. Changing entropy is only incidental to the process of eating.
     
  4. Feb 23, 2014 #3

    Andrew Mason

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    Living beings consume food to increase their store of chemical energy. Chemical energy stored in the living cells (mainly in the form of ATP) is a concentrated form of energy so it has low entropy. The living cells then burn that ATP and do useful work with it - like finding and eating more food - that eventually ends of as heat, which results in a dispersal of that once-concentrated chemical energy into the surroundings as heat. This results in an increase in entropy of the surroundings.

    AM
     
  5. Feb 23, 2014 #4
    Yes, living things do use the energy in their food to (temporarily) decrease their own entropy at the expense of increasing the entropy of the surroundings by a larger amount so that the overall effect is (as expected) an increase of entropy). Life forms are constantly using energy to reverse or prevent process that if left unchecked would lead to death. These processes increase entropy (an their reversal decreases it). One example is the imbalance of electrolytes such as chlorine, Sodium, Potassium, across membranes. These imbalances are important for normal cell function and the natural flow of ions, if left unchecked, would restore electrolyte equilibrium increasing entropy and killing the cell (or cells). Cells actively fight against those processes by pumping the ions back to where they belong. These ion pumps consume energy and decrease entropy. This is just a single example among many designed to illustrate the very general fact that the main reason life metabolic processes require energy is because they are often fighting against entropy in order to stay alive.
     
  6. Feb 23, 2014 #5
    Changing entropy is why eating is required to begin with. It's no incidental.
     
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