Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: vivian maxine on 18/09/2016 14:10:56
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According to Wiki, the biological definition of "negentropy" is different from that of the information theory definition:
I quote:
"The negentropy has different meanings in information theory and theoretical biology. In a biological context, the negentropy (also negative entropy, syntropy, extropy, ectropy or entaxy,[1]) of a living system is the entropy that it exports to keep its own entropy low; it lies at the intersection of entropy and life."
The last phrase is vague to me. Can someone please explain that as well as can someone give an example of when a living system would export entropy? I know it is to keep its entropy low but when might there be a need for the export? I am suspecting it has to do with illness but maybe I am wrong.
Thank you.
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I'm not sure I even understand the question, let alone the answer!
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Cellular configurations define lower entropy, compared to the building blocks from which they came. For example, there is more entropy in amino acids moving in water, than there is in polymerized amino acids, perfectly folded into protein. The cells many configurations define lowered entropy compared to their monomers.
The second law states that the entropy of the universe has to increase. This is a net total. A cell will offset the low entropy defined by its many structures, by increasing internal entropy in other ways. One very important source of entropy is metabolism, where large food materials are broken down and burned to produce energy. In the presence of oxygen we end up with CO2 and H2O, with the water absorbed.
The cell will export entropy, by transporting the CO2, as bicarbonate, out of the cell. The loss of the CO2 offset, causes the cell to lower entropy once again, thereby requiring more offset for its structures, resulting in more metabolism.
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Thank you, puppypower. I think that explains it. I'd not thought about CO2. Your explanation is a big help.