Please turn on javascript in your browser to play chess.
Science Forum

Science Forum

  1. 14 Aug '17 10:07 / 6 edits
    https://phys.org/news/2017-08-scientists-reveal-goldfish-alcohol-survive.html

    so they can survive for months at a time without any oxygen in the water and do so by their cells gaining energy from carbohydrates not by aerobic respiration of them but rather by anaerobic breakdown of them with the end waste product not being CO2 but rather ethanol.

    "...crucian carp, can survive for days, even months, in oxygen-free water at the bottom of ice-covered ponds.

    During this time, the fish are able to convert anaerobically produced lactic acid into ethanol, which then diffuses across their gills into the surrounding water and avoids a dangerous build-up of lactic acid in the body.

    The molecular mechanism behind this highly unusual ability, which is unique among vertebrates and more commonly associated with brewer's yeast, ....
    ...
    "During their time in oxygen-free water in ice-covered ponds, which can last for several months in their northern European habitat, blood alcohol concentrations in crucian carp can reach more than 50 mg per 100 millilitres, which is above the drink drive limit in these countries.

    "However, this is still a much better situation than filling up with lactic acid, which is the metabolic end product for other vertebrates, including humans, when devoid of oxygen."
    ..."

    This finding makes me think it is perfectly possible for a complex animal species to evolve to always live without free oxygen and complete its entire reproductive life cycle without once being exposed to free oxygen.

    It also makes me think it would eventually be possible to genetically modify humans to live and breath on another planet without any free oxygen in the planets atmosphere; a possible practical alternative to more expensive and time consuming terraforming of the whole planet. But such humans would have to be at the same time be genetically modified with neurology that is such that there is no intoxicating effects on that neurology from constant exposure to massive ethanol concentrations else they will be poisoned to death (or, if not actual death, at least dire totally unacceptable consequences for there health) by their own waste product of ethanol.
  2. Subscriber FreakyKBH
    Acquired Taste...
    14 Aug '17 18:46
    Originally posted by @humy
    https://phys.org/news/2017-08-scientists-reveal-goldfish-alcohol-survive.html

    so they can survive for months at a time without any oxygen in the water and do so by their cells gaining energy from carbohydrates not by aerobic respiration of them but rather by anaerobic breakdown of them with the end waste product not being CO2 but rather ethanol.

    "...c ...[text shortened]... dire totally unacceptable consequences for there health) by their own waste product of ethanol.
    So...
    forced evolution.
    Guided evolution.


    Makes perfect sense.
  3. Standard member sonhouse
    Fast and Curious
    14 Aug '17 19:54
    Originally posted by @humy
    https://phys.org/news/2017-08-scientists-reveal-goldfish-alcohol-survive.html

    so they can survive for months at a time without any oxygen in the water and do so by their cells gaining energy from carbohydrates not by aerobic respiration of them but rather by anaerobic breakdown of them with the end waste product not being CO2 but rather ethanol.

    "...c ...[text shortened]... dire totally unacceptable consequences for there health) by their own waste product of ethanol.
    So what drives metabolic processes, if you don't have O2, how do they power the cells, produce ATP and such?
  4. 14 Aug '17 20:35 / 3 edits
    Originally posted by @sonhouse
    So what drives metabolic processes, if you don't have O2, how do they power the cells, produce ATP and such?
    bear in mind that, even when no addition of oxygen from outside is involved, the breakdown of complex chains of most types of organic molecules, such as carbohydrates, into simpler smaller organic molecules, is generally (but not necessarily) an exothermic as opposed to an endothermic reaction, meaning it results in a net release of energy as opposed to a net absorption of energy required. So, even without O2, it is possible for a cell to gain useful amounts of energy from the breakdown of carbohydrates. But, molecule for molecule of carbohydrate, the cell cannot gain nearly so much energy without O2 because this anaerobic respiration (see https://en.wikipedia.org/wiki/Anaerobic_respiration ) is considerably less exothermic than aerobic respiration.

    In a cell, this anaerobic respiration tends to require a different set of enzymes from that of aerobic respiration because the end products is different from that of aerobic respiration. With aerobic respiration, the end products are mainly H2O and CO2 and ATP. With anaerobic respiration, the end products are H2O and ATP (albeit at the cost of much less ATP than with aerobic) but not CO2 but rather usually either lactic acid (such as produced in human muscle during anaerobic exercise) or methane (such as in bacteria in our intestines) or sometimes methanol or, in the case of yeast and these fish, ethanol.
  5. 15 Aug '17 06:50 / 2 edits
    Originally posted by @humy
    ...With anaerobic respiration, the end products are H2O and ...
    misedit; that is incorrect; the end product for anaerobic respiration generally doesn't include H2O because the breakdown of complex organic molecules into smaller simpler organic molecules in anaerobic respiration normally requires the absorption of HO2 (and between adjacent carbon atoms immediately after the enzyme has broken them), not its release.
  6. Standard member sonhouse
    Fast and Curious
    16 Aug '17 14:36 / 1 edit
    Originally posted by @humy
    bear in mind that, even when no addition of oxygen from outside is involved, the breakdown of complex chains of most types of organic molecules, such as carbohydrates, into simpler smaller organic molecules, is generally (but not necessarily) an exothermic as opposed to an endothermic reaction, meaning it results in a net release of energy as opposed to ...[text shortened]... teria in our intestines) or sometimes methanol or, in the case of yeast and these fish, ethanol.
    And these fish would survive mainly because of the lower energy requirement of the fish in general, and in a cold environment compared to human temperatures. I doubt if that could ever work for humans since we require so much more energy on a mass for mass basis.
    We run at 37 degrees and my guess is goldfish run at least 10 degrees lower. I remember from Chem class, every ten degrees the reaction energy doubles so 10 degrees lower would mean you make half the energy. I think it was degrees C. I would imagine there would be something more accurate using K.
  7. Subscriber AThousandYoung
    Do ya think?
    17 Aug '17 05:05
    So we can make goldfish beer now?
  8. 17 Aug '17 05:23
    Originally posted by @athousandyoung
    So we can make goldfish beer now?
    but it would taste and smell all fishy and horrible.
  9. 17 Aug '17 14:00
    Originally posted by @humy
    https://phys.org/news/2017-08-scientists-reveal-goldfish-alcohol-survive.html

    so they can survive for months at a time without any oxygen in the water and do so by their cells gaining energy from carbohydrates not by aerobic respiration of them but rather by anaerobic breakdown of them with the end waste product not being CO2 but rather ethanol.

    "...c ...[text shortened]... dire totally unacceptable consequences for there health) by their own waste product of ethanol.
    When I drink ethanol I get dehydrated and I take a break from drinking to give my liver a rest. You are talking about constant ethanol in the blood. How would you genetically modify a person to avoid damage to the liver?
  10. 17 Aug '17 14:37
    Originally posted by @metal-brain
    How would you genetically modify a person to avoid damage to the liver?
    by genetically modifying the liver cells, along with all the other types of human body cells, so that they remain undamaged by massively high concentrations of ethanol within them ( + don't chemically breakdown the ethanol else this scheme wouldn't work ).
    To do that, must take into account how massively high concentrations of ethanol normally damages cells.
    This must be possible because certain yeast cells and the cells of goldfish can withstand massively high concentrations of ethanol within them without them being damaged!
  11. 17 Aug '17 15:14
    Originally posted by @humy
    by genetically modifying the liver cells, along with all the other types of human body cells, so that they remain undamaged by massively high concentrations of ethanol within them ( + don't chemically breakdown the ethanol else this scheme wouldn't work ).
    To do that, must take into account how massively high concentrations of ethanol normally damages cells. ...[text shortened]... h can withstand massively high concentrations of ethanol within them without them being damaged!
    Yeast excretes alcohol as waste in to the beer wort or wine. How would a genetically modified person do that? Urination would be a convenient way, but is that possible without any help from the liver?
  12. 17 Aug '17 17:52 / 6 edits
    Originally posted by @metal-brain
    Yeast excretes alcohol as waste in to the beer wort or wine. How would a genetically modified person do that? Urination would be a convenient way, but is that possible without any help from the liver?
    Yeast excretes alcohol as waste in to the beer wort or wine. How would a genetically modified person do that?

    by genetically modified person's cells to be like that of goldfish cells which do just that.
    Urination would be a convenient way, but is that possible without any help from the liver?

    Urination is possible because of the kidneys, not the liver. Urination isn't directly helped by the liver because urine comes from the kidneys, not the liver which has very little if anything to do with it although no doubt there must sometimes be some indirect complex interactions.
    I assume goldfish kidneys filter out the ethanol for excretion although I am unsure of exactly how fish biology differs from human biology so I could be partly wrong about that miner detail because it could be, for all I know, that the ethanol leaves the goldfish's body mainly through the gills rather than mainly via its kidney function. But, either way, its liver would have nothing to do with that.
  13. 17 Aug '17 18:16 / 6 edits
    Originally posted by @sonhouse
    And these fish would survive mainly because of the lower energy requirement of the fish in general, and in a cold environment compared to human temperatures. I doubt if that could ever work for humans since we require so much more energy on a mass for mass basis.
    We run at 37 degrees and my guess is goldfish run at least 10 degrees lower. I remember from ...[text shortened]... nergy. I think it was degrees C. I would imagine there would be something more accurate using K.
    The answer would be for the humans to make up for that by eating something like ~20 times more mass of carbohydrates and make sure they never go short of food for more than only ~3 days, which would be about how long these anaerobic humans will take to starve to death.

    Actually, now I consider this and other constraints and ifs and buts with this idea of mine, although I still think it is possible and doable (in the far future when it becomes technically feasible), I now think it would be just too problematic to ever be worth doing. Just for starters; do you really want to have to more-or-less constantly non-stop eat like a pig to stop yourself from very rapidly starving to death?
  14. Standard member sonhouse
    Fast and Curious
    17 Aug '17 18:27
    Originally posted by @humy
    The answer would be for the humans to make up for that by eating something like ~20 times more mass of carbohydrates and make sure they never go short of food for more than only ~3 days, which would be about how long these anaerobic humans will take to starve to death.

    Actually, now I consider this and other constraints and ifs and buts with this idea of mi ...[text shortened]... or-less constantly non-stop eat like a pig to stop yourself from very rapidly starving to death?
    Imagine trying to apply for a grant to study this.....
  15. 17 Aug '17 18:29 / 3 edits
    Originally posted by @sonhouse
    Imagine trying to apply for a grant to study this.....
    I think I definitely should give up on that.
    It is hard enough getting a grant to study something that I think is worthy of study.
    It is very fortunate that I don't need a grant for my current research, which I can afford to do and happily do do in my spare time and entirely at my own expense.