Notices
Results 1 to 7 of 7

Thread: Figure it Must Come from Us

  1. #1 Figure it Must Come from Us 
    Time Lord zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    5,754
    Biochem question: If we breathe in oxygen and exhale CO2 then where does the carbon come from? Must be from us but I’m not losing any weight by breathing, or am I gaining?…lol

    If the air we breathe contains carbon then does that affect our body’s CO2 emissions also? I’m thinking that if we expel our carbon at a certain set rate then that could increase if we also have to exhale the carbon we inhale with each breath or does too much carbon in the air mean I don’t get rid of as much of my own? Is this why I should stay away from carbohydrates?


    Last edited by zinjanthropos; October 7th, 2021 at 08:22 AM.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Senior Double Helix's Avatar
    Join Date
    Dec 2020
    Posts
    324
    Quote Originally Posted by zinjanthropos View Post
    Biochem question: If we breathe in oxygen and exhale CO2 then where does the carbon come from? Must be from us but Iím not losing any weight by breathing, or am I gaining?Ölol

    If the air we breathe contains carbon then does that affect our bodyís CO2 emissions also? Iím thinking that if we expel our carbon at a certain set rate then that could increase if we also have to exhale the carbon we inhale with each breath or does too much carbon in the air mean I donít get rid of as much of my own? Is this why I should stay away from carbohydrates?

    The carbon comes primarily from metabolism of carbohydrates, proteins and fats that you eat. You will only lose weight due to insufficient intake.

    These nutrients are broken down to produce adenosine triphosphate (ATP), an energy carrier for most biochemical reactions. The products are CO2 and water.

    The process is known as cellular respiration :

    https://en.wikipedia.org/wiki/Cellular_respiration


    Carbohydrates are an essential component of human metabolism. Your brain works almost exclusively from the metabolism of glucose :

    https://www.ncbi.nlm.nih.gov/books/NBK22436/


    Reply With Quote  
     

  4. #3  
    Time Lord zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    5,754
    Thanks DH. The way I see it is that we all have a an amount of carbon stored but what I don’t know is if the body exhales carbon at a specific rate. It’s probably different for everybody but does the body have a specific rate that hardly varies? Per normal exhalation, does your body expel the same amount of carbon for each breath taken, whether breathing fast or slow? If you are predisposed to only a certain amount or maximum per exhalation and it’s less than someone else’s all things considered equal, will you lose weight at a slower rate than the other guy? Just wondering if something like breathing has an affect on weight loss. Seems to me like the more carbon you can get rid of means weight loss.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  5. #4  
    Bullshit Intolerant PhDemon's Avatar
    Join Date
    Feb 2013
    Location
    Newcastle-upon-Tyne, UK
    Posts
    5,562
    Quick back of the envelope calculation (I actually asked a student to calculate this in a mock interview this week!)

    Tidal volume of lungs (normal breathing) is approx 500cc
    Exhaled air contains about 4% CO2
    So we have 500 X 0.04 = 20cc of CO2 per breath.

    Say 15 breaths per minute and we get 432000 cc CO2 per day.
    Molar volume of CO2 is approx 24000 cc

    So per day you exhale about 18 moles of CO2.
    This corresponds to about 792g of CO2 (or 216g) of carbon.

    So by breathing normally for a day you will lose 216g (about 7.6 Oz) of carbon. This will be increased by breathing heavily or faster but the amount of carbon lost through respiration won't be significant in terms of loss of body weight.

    To complicate matters you also exhale a lot of water but breathing still isn't a significant weight loss activity!
    Reply With Quote  
     

  6. #5  
    Time Lord zinjanthropos's Avatar
    Join Date
    Dec 2005
    Location
    Driving in my car
    Posts
    5,754
    Quote Originally Posted by PhDemon View Post
    Quick back of the envelope calculation (I actually asked a student to calculate this in a mock interview this week!)

    Tidal volume of lungs (normal breathing) is approx 500cc
    Exhaled air contains about 4% CO2
    So we have 500 X 0.04 = 20cc of CO2 per breath.

    Say 15 breaths per minute and we get 432000 cc CO2 per day.
    Molar volume of CO2 is approx 24000 cc

    So per day you exhale about 18 moles of CO2.
    This corresponds to about 792g of CO2 (or 206g) of carbon.

    So by breathing normally for a day you will lose 216g (about 7.6 Oz) of carbon. This will be increased by breathing heavily or faster but the amount of carbon lost through respiration won't be significant in terms of loss of body weight.

    To complicate matters you also exhale a lot of water but breathing still isn't a significant weight loss activity!
    Just so you know, I’m not that student nor have I asked my questions anywhere else That damn universe simulator guy likes coincidences.

    The less exercise or rapid breathing I do will reduce my CO2 contribution to the atmosphere, so perhaps a sedentary lifestyle will slow global warming.

    Out of curiosity, don’t we inhale carbon already present in the air with each breath?
    Last edited by zinjanthropos; October 8th, 2021 at 09:11 AM.
    All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by no appearance of probability...Hume
    Reply With Quote  
     

  7. #6  
    Forum Senior Double Helix's Avatar
    Join Date
    Dec 2020
    Posts
    324
    Quote Originally Posted by zinjanthropos View Post
    Out of curiosity, don’t we inhale carbon already present in the air with each breath?
    Certainly. Carbon monoxide is a classic example of this, with its potentially nasty results. It is an unfortunate component of exhaust fumes from cars, etc.

    We can also breath in CO2, for instance by re-breathing into a paper bag. This has often been cited as a means to calm anxiety attacks (1).

    You can also get drunk breathing in ethanol (2). You miss out on the flavor of the drink, of course, but you can get the same "high".

    And there are many other carbon containing compounds in the air from various sources. Methane is everywhere, as are many volatile compounds from the extraction and use of hydrocarbons (e.g. benzene every time you fill your gas tank). They can all dissolve in your blood when inhaled, to some extent.

    There is no getting away from carbon, from one source or another.


    "Breathing into a paper bag can calm anxiety attack"

    1. https://connect.uclahealth.org/2020/09/16/breathing-into-a-paper-bag-can-calm-anxiety-attack/


    "Alcohol inhalation"

    2. https://en.wikipedia.org/wiki/Alcohol_inhalation
    Last edited by Double Helix; October 8th, 2021 at 04:39 PM.
    Reply With Quote  
     

  8. #7  
    Bullshit Intolerant PhDemon's Avatar
    Join Date
    Feb 2013
    Location
    Newcastle-upon-Tyne, UK
    Posts
    5,562
    Yes but the air you breath in is about 0.04% CO2, and other carbon containing gases are generally lower than this. This is swamped by the CO2 produced during respiration. Breathed out air is about 4% CO2.
    Reply With Quote  
     

Similar Threads

  1. Father Figure
    By Jim Colyer in forum Art and Culture
    Replies: 7
    Last Post: December 29th, 2013, 02:56 PM
  2. Help me figure this out
    By Cyberdroid in forum Physics
    Replies: 11
    Last Post: November 15th, 2012, 11:04 PM
  3. I can't figure this out!
    By m84uily in forum Mathematics
    Replies: 2
    Last Post: April 1st, 2011, 06:39 PM
  4. machine figure
    By mcjason in forum General Discussion
    Replies: 0
    Last Post: July 23rd, 2008, 08:59 PM
  5. machine figure
    By mcjason in forum Computer Science
    Replies: 0
    Last Post: July 23rd, 2008, 08:58 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •