Talk:Essential amino acid
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Article Grading: The following comments were left by the quality and importance raters: (edit · history · refresh · how to use this template) What is the source for the table? I cannot find this information on the WHO website. |
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[edit] Random comments
Some moron added a load of grammatically incorrect and confusing content. I would revert, but there have been several edits since then and no one has fixed it for some reason. Also, the information may be helpful but it has also not been verified. The single WHO citation is incorrect. I have added template messages to the article. Please explain before removing them if necessary. 67.171.43.170 01:30, 29 May 2006 (UTC)
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Use of Amino Acids as nutritional supplement? I was looking around the amino acids page for information on this topic, but could not find it. Amino Acid liquid supplements are sold at GNC and other health food outlets for use by athletes, body builders, calorie restrictive dieters, and other health conscious people. Could someone who is knowledgeable about the pros and cons of using these supplements please post something about it? --Alecke1 01:31, 29 August 2005 (UTC)
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Hey, I was taught a great little acronym to remember the essential amino acids, it's Private Tim Hall, or more accuratly, PVT TIM HALL. You need to know all the amino acids comfortably enough to figure out what each letter stands for (first letter of each name not IUPAC abbr. ), but I use it all the time in school and work, and I know other people do too, you guys/gals think it would be a worthy addition to this page? Adenosine | Talk 06:38, August 5, 2005 (UTC)
- I'll go ahead and add that in as a mnemonic device. - --Alecke1 01:31, 29 August 2005 (UTC)
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A common addition to this is PVT TIM HALL, always argues, never tires. This is to remember that arg is the a and tyrosine is not an essential amino acid. —Preceding unsigned comment added by 144.118.131.52 (talk) 21:29, 16 February 2008 (UTC)
This comment doesn't belong on the main page, but...
One irony in Sheri Tepper's science fiction novel Grass (in my opinion, an otherwise excellent work) is that in her world, people suffer from a terrible deficiency disease which affects alanine. As stated previously, alanine is not essential and can be synthesized from pyruvate. David M
- Of course, if one mentally substitutes phenylalanine for alanine, then at least it becomes plausible, which begs the question of which editor missed this gaffe as well. David M
The standing issue I haven't been able to resolve to my satisfaction is the nature of arginine biosynthesis in humans. arginine can be synthesized from either ornithine or citrulline via the urea cycle, which of course begs the question of whether in humans, this is a closed system or open. In other words, can carbon equivalents be fed into this cycle or does it require a source of one of these three amino acids? I know that in some bacteria there are precursers to ornithine because of constant net-references to genetic knock out studies. But does this precurser -> ornithine biosynthetic pathway exist in humans? This I haven't found out yet. Dated Oct 11, 2002. David M
[edit] Is Taurine essential ? (to humans)
Can anybody shed any light on whether Taurine is essential to humans. Is it synthesised in humans? or is our ability to synthesis it related to age?
- Well we need it, but it can be synthesised by us to a certain extent.
- Is taurine essential?
- Taurine is a conditionally essential amino acid in adult humans; it is an essential amino acid for infants (mother's milk contains taurine). Gaull [1982, p. 90] discusses the need for taurine:
- The finding of a dietary requirement for taurine in the human infant is consistent with the negligible activity of cysteinesulfinic acid decarboxylase present both in fetal and in mature human liver (4)...
- In adult man only 1% of an oral load of L-cysteine was recovered as increased urinary excretion of taurine, giving further evidence that mature human beings also have a relatively limited ability to synthesize taurine and may be largely dependant on dietary taurine (22). The rat, in striking contrast, has considerable ability to convert dietary cysteine to taurine (17).
- See also Gaull [1977] as cited in Gaull [1982, 1986] for more information on taurine synthesis in humans vs. other animals.
[edit] arginine biosynthesis + mnemnonic
ornithine biosythnesis in mammals competes with proline biosynthesis
alpha keto glutarate + NH4+ --> glutamate --> gamma glutamyl phosphate --> glutamyl semialdehyde --> ornithine
(comapared to alpha keto glutarate + NH4+ --> glutamate --> gamma glutamyl phosphate --> glutamyl semialdehyde --[non enzymatic schiff base formation]--> delta- pyrroline 5 carboxylate --> proline + CO2
in plants, you add an acetyl blocking group to avoid competition with proline
conclusion; ornithine, and therefore arginine can be biosynthesized from scratch. the only problem is that infants have trouble synthesizing enough... so for kids, arginine is essential amino acid
i'd like to take up a complaint with the mnemnonic provided... its too misleading; a better one would have to based on the official amino acid single letter designation i.e.
MLKR HIV WTF
ya. thats lame, i know... but it will get me through my biochem final next week
my point is, find a better mnemnonic... using simply the first letter of each amino acid is too confusing... there are many amino acids beginning with the same letter
[edit] Sources of Proteins
Can nuts be added to this little table? —The preceding unsigned comment was added by 65.92.189.213 (talk) 04:40, 6 December 2006 (UTC).
[edit] Legumes need to be added to "Limiting amino acid" chart
- From the peanut page, they lack Lysine, Cystine, and Methionine
- The soy bean page claims soy beans are a complete protein
- Other beans are missing some, but I'm not sure which.
[edit] Limiting amino acid
Why is the limiting amino acid the essential acid whose concentration is lowest, instead of the essential amino acid whose concentration divided by the recommended daily intake is lowest? Applying the latter criterion seems to always make methionine the limiting amino acid. Icek 21:46, 27 April 2007 (UTC)
The article suggests that it is necessary to eat complementary protiens, else the limiting amino acid will force the remaining protien to be "wasted". This is still true, however, there is plenty of research today that says complementary proteins consumed within day's time of each other is sufficient; it does not have to be the same meal.
Yes, the concept seems to have been misunderstood: the limiting amino acid is the one without which the other aminoacids are useless for protein synthesis. I.e. if you need ten Mols of lysine to make a protein that contains 5 Mols of Arg, 6 Mols of Met and 11 Mols of Tyr, then having tons of the other aminoacids still doesn't allow you to make more than two Mols of the protein, if you only have 20 Mols of lysine. 85.178.31.153 (talk) —Preceding comment was added at 15:05, 4 March 2008 (UTC)
[edit] BCAA
Why is there no seperate article on branch chain amino acids?....
[edit] 9 or 10 e.a.a's?
The amino acid article says there are 10 essential amino acids. The Essential Amino Acid article (this one) starts by saying there are 9, but it contains a table that lists 10. I'm just a knowledge-seeking passer-by, so I wouldn't presume to edit the article myself, but can I ask the experts to remove this obvious discrepancy?
Kkken 09:48, 10 July 2007 (UTC)
[edit] why is hemp not included on this page?
hemp protein is a source of all 10 essential amino acids, as well as 8 others including alanine, aspartic acid, cystine, glutamic acid, glycine, proline, serine, and tyrosine.[2] *i believe it's the most complete source of protein out there?* Dubyuh 20:27, 26 July 2007 (UTC)
[edit] Mnemonic
The wording implies that "I Like Light That Tries Making Home Very Pretty" is a well-known mnemonic, but a Google search really doesn't support that view at all - two hits, both relating to this article! 86.149.1.65 03:27, 20 August 2007 (UTC)
[edit] Unreferenced section
I tagged one section as unreferenced; not only is it OR at this point, but the second paragraph appears to be a defense of vegetarianism, which isn't really appropriate here but definitely needs a source if it's going to stay. Mr. Darcy talk 04:32, 20 August 2007 (UTC)
[edit] Use of essential amino acids
I wrote (many years ago) an early version of the first and third paragraphs of the limiting amino acid/net protein utilization section. The discussion derives directly from lecture notes given by Professor James Walker of Rice University in the spring of 1981, and also from the textbook of McGilvery (ISBN 0-7216-5912-8), in particular chapter 41. Now that second paragraph is nothing I recall or would entirely agree with, but I admit to being a hard core carnivore. Dwmyers 23:54, 18 September 2007 (UTC)
- Oddly enough (and I don't agree with this rule), lecture notes are not considered good sources around here unless they have been published or at least posted by the professor online. But the textbook, if the page is given, will certainly be valid. Glad to see you editing again. :) --mav 17:14, 19 September 2007 (UTC)
[edit] Legumes and pulses
The legume and pulse "limiting amino acids" are listed as different; but aren't all pulses legumes? This section needs a reference, too.... --Macrakis (talk) 21:48, 10 February 2008 (UTC)
[edit] POV issue with food listing
POV: where's the meat? 122.200.166.29 (talk) 13:00, 15 May 2008 (UTC)
- Should be fixed now. If it's not, please provide more explanation of what the problem is. Thanks. --DachannienTalkContrib 13:35, 15 May 2008 (UTC)
