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Amino acid versus protein

  1. Apr 12, 2016 #1
    I got a question, consuming amino acid and consuming protein is the same thing right? Protein is a chain of amino acids but it does not really change their properties by becoming protein right?
  2. jcsd
  3. Apr 12, 2016 #2
    Hi fred:
    The chemical properties of a protein are entirely different from those of its amino acid constituents, and it reasonable to call them "emergent properties".
    One example of these emergent properties is a protein's enzyme properties. The individual amino acids don't have enzyme properties

    Hope this helps.

  4. Apr 12, 2016 #3


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    But the question was about consuming them. You eat proteins, but by the time have passed to they have been broken down (I.e. hydrolysed by 'proteolytic' enzymes) to amino acids. Then your own proteins are built from these. So to a first approximation you could survive by consuming amino acids and no proteins.

    Whether it would do you good, e.g. because of effects on gut bacteria and the digestion of other things and other unforeseebles is another matter. We do not advise on medical questions here.

    (There is a bio market for aminoacid supplements to ad to diets, e.g. methionine which is laccinge in salme people's diets - e.g. If they depend on maize. However all this stuff is easy to find online.)
  5. Apr 12, 2016 #4
    Hi epenguin,
    Buzz is saying that protein has enzymatic properties which can synthesize or break down molecules on its own, before it gets turned into amino acids I suppose?
  6. Apr 12, 2016 #5
    Hi epenguin and fred:
    I apologize for not being clearer.

    I intended to suggest that it is possible that a protein might have a different effect in the digestive process than its amino acid constituents, but I have no idea if this has ever been demonstrated. I am guessing that most proteins that are consumed are not enzymes, but I think it is plausible that any protein may have some emergent property that could have an effect during digestion. AFAIK, proteins might cause allergic reactions.

    Here is an example:

  7. Apr 12, 2016 #6

    jim mcnamara

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    Let's look at it this way. Take chicken soup for an example.

    Please do not take this as advice to eat raw meat, but it should be obvious that raw chicken meat does not taste the same as cooked meat in soup - for a lot of reasons.

    One reason is that a fraction of proteins are hydrolyzed during cooking - broken down into polypeptides and into some single amino acids. Polypeptides are short chains of amino acids. So in a sense every time you have chicken soup you are consuming some amino acids.

    Food intolerance and allergenic responses are a lot more complex. And @Buzz Bloom is correct in saying that by consuming protein as straight amino acids gut activity and responses may change. But not necessarily for the worse.

    Some infant formulas (EHF's) are made from extensively hydrolyzed cow's milk proteins. Note this means lots of different polypeptides. This paper cites using pure amino acid mixtures in lieu of EHF for EHF sensitive infants. The take away is that the immune system does not see the amino acids as allergenic, but does react to a few of the huge panoply of polypeptides present in EHFs.

    (abstract only behind a paywall ) http://www.sciencedirect.com/science/article/pii/S0022347697701045?np=y

    This is in counterpoint to what @Buzz Bloom was mentioning. IMO, it is possible to have adverse effects from changing diet to include only amino acids, yes. It is something to expect? probably no. The downside of "losing meat" is a concomittant decrease in non-caloric nutrients in the total intake - mineral nutrients, some vitamins, specifically vitamin B12. Obviously vegans have worked out a way around this, so this is not a blanket statement.

    Plus, so-called branched chain amino acids (leucine, isoleucine and valine) are routinely used as a supplement by weight lifters and some endurance athletes.
    There are data to support this application:

    However let's not go off on the whole supplement thing. Please. I put this in here to counter the argument that the use of straight amino acids in the diet is very rare. Apparently not so rare.
    Last edited: Apr 12, 2016
  8. Apr 12, 2016 #7
    Hmm, epenguin might have a point here in saying that only amino acids are required. Well the point is that not all protein are enzymes. And out of all the proteins that we consume from fish, egg, milk, I am not sure if any of them act as enzymes. So the point is, if any protein we eat acts as an enzyme and it is essential then we cannot survive based on amino acids alone. Otherwise our body can make its own enzymes and all we need are essential amino acids. Nothing medical here, just scientific ideas, please don't ban me D:
  9. Apr 12, 2016 #8
    Hi Fred:

    I think you have a misunderstanding about the digestion of proteins. The digestive process always breaks down proteins into amino acids. It is impossible to get useful enzymes in to the blood by eating them. That is why insulin in injected.

  10. Apr 12, 2016 #9
    Right the PH in the stomach would break it, points taken...
  11. Apr 12, 2016 #10

    jim mcnamara

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    Enzymes are long chains of amino acids. If you cook meat, then you denature protein - that is you irreversibly alter proteins. So what happens to enzymes during cooking? They are denatured. What happens to enzymes in raw food? They may function for a while until they too 'bite the dust' so to speak.

    Since raw egg and raw meat are problematic because of possible food-borne pathogens, I do not see a big problem. Plus enzymes derived from raw foods do have a half-life in the gut during digestion - this article uses the term 'novel proteins'

    So a fair statement of about ingesting enzymes in raw foods: they may be active for a short time. At any rate, non-caloric nutrients are MUCH more important to consider when going to a diet of amino acids only. Aside from the fact that this dietary approach is blatantly not practical, since most foods humans eat have some protein content. The exception being infants. So unless you are under 1 year old: Eat the real foods that are available to you.

    Example of a failure when trying to create a completely synthetic diet - i.e., one straight from the lab bench: the bruhaha caused by Gerber infant formula long ago. Chloride (Chlorine atom) (in TINY amounts) is a required nutrient. The formula had none. Bottle fed infants on the Gerber formula failed to thrive. I cannot find a decent citation - apparently the fringe faction on the internet has flooded everything with chlorine scares about bleach and perchlorate induced contaminants in foods. While this may be valid (or not), it kinda precludes finding ancient articles on the chloride problem.

    Here is the best I can do:
  12. Apr 14, 2016 #11


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