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Regarding this piece: "After removal of one or more amino groups, the remainder of the molecule can sometimes be used to synthesize new amino acids, or it can be used for energy by entering glycolysis or the citric acid cycle, as detailed in image at right."
I think someone could add gluconeogenesis, at least, and maybe also the ketogenic pathways.
I also wasn't aware of aminoacids entering glycolysis, unless it was for gluconegoenesis, and the image on the right also doesn't show any support to it. In the end, it would be like: citric acid cycle, (glycolysis), ketogenesis, and gluconeogenesis
I just won't edit it by my own decision, I suppose.
-- Orangutan45 ( talk) 05:03, 24 May 2016 (UTC)
Why are all the amino acids not shown in their zwitterionic forms in the main svg? At physiological 7.4 pH, this is what they would be, right? Moine Bouddhiste ( talk) 12:28, 12 November 2016 (UTC)
Should there not be a positive charge on the NH of the imidazol ring of histidine at physiological pH? — Preceding unsigned comment added by Moine Bouddhiste ( talk • contribs) 14:08, 12 November 2016 (UTC)
This is old terminology. According to the IUPAC Gold Book, an imino acid needs to have both imine and carboxyl functional groups. Proline instead has a secondary amine group. Double sharp ( talk) 11:26, 26 November 2016 (UTC)
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It's huge -- 555 words. That's surely too long. I don't have the interest or expertise, but hope someone else does. 60.248.185.19 ( talk) 05:16, 1 June 2018 (UTC)
I'm not sure how or where to put it, but some explanation of how d-amino acids interact with multi-cellular biochemistry should be included. I have found various references to "d-amino acids are toxic to humans" on the internet, but none of them explain how. The sources I have found that say that are mostly abstracts for biochemical papers, so I assume they know what they are talking about. Nevertheless, this article does not even contain the statement "D-amino acids are toxic to most life" or its converse "d-amino acids are benign to most life". 66.219.236.172 ( talk) 07:11, 8 July 2018 (UTC)
This is entirely new to me (editing wikipedia). The section heading "D-amino acid natural abundance" is badly out of date. I recommend consulting a recent review article, Genchi, Giuseppe 2017. An overview on D-amino acids. Amino Acids, 49(9), pp.1521-1533.
https://link.springer.com/article/10.1007/s00726-017-2459-5
It is open to the public and is very good. — Preceding unsigned comment added by Gary S. Hurd ( talk • contribs) 18:31, 28 July 2019 (UTC)
Some Human Genetic Disorders Affecting Amino Acid Catabolism is a recently created subsection with a table, under Catabolism. Is it possible that the table was copied verbatim from the reference: Jain, J. L. Fundamentals of biochemistry. New Delhi: S. Chand and Co. ISBN 8121903432. OCLC 818809626. David notMD ( talk) 09:24, 25 September 2019 (UTC)
May I suggest this improved version of the first sentence in the second paragraph that begins,'In biochemistry, amino acids having both the amine and the carboxylic acid groups attached to the first (alpha-) carbon atom have particular importance.'
In biochemistry, because amino acids have both the amine and carboxylic acid groups attached to the first (alph-) carbon atom they have particular importance.
Or better still,
Amino acids have both the amine and carboxylic acid groups attached to the first (alph-) carbon atom making them particularly importance in biochemistry.
I am not game to edit things directly, but a lot of Science articles are less well written than they could be. We live in a shockingly polarised world where people stream their education and end up either Literate or Numerate, but rarely both.
Of course, the second Paragraph begins with essentially the same content as the first, which is very poetic, but extends the article making it daunting to read. Yet it is of such fundamental importance. We are mostly made of two things and this is about one of them. There is so much to think about on so many levels and in so many dimensions. See!! I am not reading it now.
NaumTered 22:18, 28 August 2020 (UTC) — Preceding unsigned comment added by Norm Tered ( talk • contribs)
In the lead, in the sentence, "In the form of proteins, amino acid residues form the second-largest component...", would it be ok to link the whole term ' amino acid residues' (as I have done here) to the specific sub-section in the chemistry article which does eventually explain 'residue' in a biochemical/protein context, instead of as it is currently, which just links the single word ' residues' to the whole chemistry article about residues in general? That article starts by giving a more general definition of 'residue', which general definition could initially be confusing to some. Further on down in that article is the relevant sub-section which defines residue in a more protein-relevant manner, and that's what I would think to link directly to. UnderEducatedGeezer ( talk) 04:36, 28 December 2020 (UTC)
The amino acid in the main figure had D configuration. This might be confusing for some readers as mostly L-amino acids are used in biology, industry, research etc. I myself tried to figure if the stereoisomer I drew is in the correct configuration by comparing to that image. Luckily I compared also with other sources. 185.175.34.246 ( talk) 12:03, 13 June 2021 (UTC)
{{ping User:Smokefoot, User:Smokefoot, User:DMacks}} There are a great many things to be corrected in this article and I plan to do some serious editing in the next few days or weeks. I'm mentioning it here because some experts will disagree with my edits, and I want to give them the opportunity to say so. Ideally, many of the figures should be redrawn, but I'm not sure that I have the skill for that. Athel cb ( talk) 09:18, 15 September 2021 (UTC)
Stimulated by the question above about toxicity of D-amino acids I have been searching for a reliable source of information. I have located my Merck Index, but it does not include systematic information about that. Likewise the Rubber Book and two encyclopaedias of biochemistry that I have. I have searched Web of Science for "LD-50" AND "amino acid" and similar search strings, but although I get vast numbers of hits I haven't found anything useful. Yet there has to be a table somewhere on LD-50 values. Any suggestions? Athel cb ( talk) 13:29, 21 September 2021 (UTC)
In the figure for cationic side-chains, the fixed cation on the arginine side chain should read H2N+= rather than H3N+=. Citation: Wikipedia's own Arginine entry, among many others. — Preceding unsigned comment added by 99.165.76.203 ( talk) 14:44, 9 November 2021 (UTC)
Beginning at the second paragraph, there's a fairly editorial description of UIPAC naming convention that puts too much weight on the rarity of the structure in nature. Especially the word "fictitious," use of scare quotes, and repeating part of a probably unnecessary quote. Same bias seems to affect the caption. This may be an important issue, but deserves at most a brief mention in the lead. At least that's how it struck me. Yellowdesk60 ( talk) 17:43, 2 January 2022 (UTC)
I quote:
Isn't that an immediate contradiction? How could "the first few" amino acids have been discovered in the "early 1900s" when several were discovered in the previous century? -- 123.243.244.238 ( talk) 10:24, 3 March 2022 (UTC)
At certain points, the article becomes unusually passionate about this notion that the names "aspartic acid" and "glutamic acid" are incorrect (see the "Anionic side-chains" subsection) and that the only correct names are "aspartate" and "glutamate". It currrently says about the acid names: "Although the misnomer is so widespread as to be ineradicable, they should not be called acidic amino acids, because they act as Brønsted bases in all circumstances except for enzymes like pepsin that act in environments of very low pH like the mammalian stomach." (bold/italic emphasis already there in the article)
I'd like the opinion of other (bio)chemists on this. I call this overly pedantic. I want to point out that this choice is inconsistent with the names of their corresponding Wikipedia pages (currently Aspartic acid and Glutamic acid), and that the acid names are used regularly in the primary and secondary literature by (bio)chemists themselves without controversy. Also, many students are likely to encounter the acid names in their first exposures. We do not emphasize that "amino acids" are "ammonium carboxylates" at all physiological pH values or that "arginine" is "argininium", and I think these would be similarly correct-yet-too-pedantic changes to make.
In the meantime, I will edit the tone to be less aggressively "anti-acid" because I think it does not contribute to the helpfulness of the article more than a neutral discussion of nomenclature would. TungstenEinsteinium ( talk) 18:30, 2 May 2022 (UTC)
This sentence is outdated. Some sources there are actually 22 [1] [2] amino acids which participate in in-vivo protein synthesis, listed below:
{{
cite journal}}
: CS1 maint: url-status (
link)
— CrafterNova [ TALK ] [ CONT ] 17:23, 7 May 2022 (UTC)
I think it may be good to add at least very brief info from/about this study and/or similar articles to the article. It's currently featured in 2022 in science like so:
Scientists report the discovery of chemical reactions by potential primordial soup components that produced amino acids and may be part of the origin of life on Earth. [1] [2]
More generally and beyond this study in specific, please add some info about how amino acids are thought to relate to the origin of life on Earth ( abiogenesis) and are thought to originate, including with some brief info in the lead. I find it strange that this seems to be entirely missing in the article if I haven't only overlooked it.
Useful sources for this may include: " Amino acids and the origin of life on Earth", " The origin of the biologically coded amino acids", " Undefining life's biochemistry: implications for abiogenesis" and " Small Cofactors May Assist Protein Emergence from RNA World: Clues from RNA-Protein Complexes".
References
Prototyperspective ( talk) 17:16, 2 September 2022 (UTC)
The diagram shows histadine without a charge on its side chain, but it is lumped in with Group A. Conversely, selenocysteine is shown with a charge on its side chain and yet is *not* in Group A. I would like to know why, and I think a lot of readers would. Also, I'd like to know what "Special Cases" (defining Group C) means. How about clarification regarding this in the caption to the diagram? Polar Apposite ( talk) 10:12, 15 November 2022 (UTC)
I edited the aliphatic side-chains section. I added "therefore" to "do not ionize", reversed the positions of isoleucine and leucine to match the General Structure chart, and added phenylalanine. I am a layman so I would appreciate a chemist checking my work here. Polar Apposite ( talk) 17:29, 17 November 2022 (UTC)
It says, "The water-soluble proteins tend to have their hydrophobic residues (Leu, Ile, Val, Phe, and Trp) buried in the middle of the protein, whereas hydrophilic side chains are exposed to the aqueous solvent." 1. Shouldn't the full names rather than the three-letter symbols be used? 2. Can a residue with a hydrophobic side chain not be hydrophobic? If so, is like being compared to like when a list of residues is contrasted with a type of side chain? 3. Is it the hydrophobic side chain that tends to be buried in the middle of the protein, or the whole residue? 4. The diagram near the top of the article lists *eight* hydrophobic (with a hydrophobic side chain, if that's different) amino acids, so is that list of five correct? Polar Apposite ( talk) 18:15, 19 December 2022 (UTC)
It says in the caption to the color chart,"The 21 proteinogenic α-amino acids found in eukaryotes, grouped according to their side chains' pKa values and charges carried at physiological pH (7.4)" but the pKa values of most of the side chains of the alpha-amino acids are not shown, and it very much looks to me that they are grouped according to hydrophobicity, and so on, as it says in the chart and ordered according to increasing complexity going from left to right, at least in the section containing the eight amino acids classified as having a hydrophobic side chain. Furthermore, in the few cases where the pKa value of the side chain is shown, there is no grouping according pKa value that I can see. Arg, His, and Lys are in the one group but the pKa value of the side chain is 12.10, 6.04, 10.67 respectively, while Tyr, which has a side chain pKa of 10.10, which would seem to indicate that it should be grouped with those three is instead in another group. Polar Apposite ( talk) 16:55, 10 January 2023 (UTC)
The following section was removed because it did not appear to fit in with the main theme, amino acids, but maybe I am mistaken:
Dietary exposure to the nonstandard amino acid BMAA has been linked to human neurodegenerative diseases, including ALS. [1] [2]
-- Smokefoot ( talk) 18:15, 29 September 2023 (UTC)
References
The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
Because of an overload of chemistry articles at GAR, if delisting, do not close before 1 March.
Looks like there's some amounts of uncited material including
Most of side chains looks uncited but I think citation 6 is supposed to be one large general reference. Though I'm not sure. Either way, the things above will need to be cited. Onegreatjoke ( talk) 22:15, 8 February 2023 (UTC)
This is the
talk page for discussing improvements to the
Amino acid article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
Archives: 1, 2, 3 |
Amino acid has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it. | |||||||||||||||||||||||||
|
This
level-4 vital article is rated GA-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | |||||||||||||||||||||||||||||||||||||||||||||||
|
Daily pageviews of this article
A graph should have been displayed here but
graphs are temporarily disabled. Until they are enabled again, visit the interactive graph at
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Regarding this piece: "After removal of one or more amino groups, the remainder of the molecule can sometimes be used to synthesize new amino acids, or it can be used for energy by entering glycolysis or the citric acid cycle, as detailed in image at right."
I think someone could add gluconeogenesis, at least, and maybe also the ketogenic pathways.
I also wasn't aware of aminoacids entering glycolysis, unless it was for gluconegoenesis, and the image on the right also doesn't show any support to it. In the end, it would be like: citric acid cycle, (glycolysis), ketogenesis, and gluconeogenesis
I just won't edit it by my own decision, I suppose.
-- Orangutan45 ( talk) 05:03, 24 May 2016 (UTC)
Why are all the amino acids not shown in their zwitterionic forms in the main svg? At physiological 7.4 pH, this is what they would be, right? Moine Bouddhiste ( talk) 12:28, 12 November 2016 (UTC)
Should there not be a positive charge on the NH of the imidazol ring of histidine at physiological pH? — Preceding unsigned comment added by Moine Bouddhiste ( talk • contribs) 14:08, 12 November 2016 (UTC)
This is old terminology. According to the IUPAC Gold Book, an imino acid needs to have both imine and carboxyl functional groups. Proline instead has a secondary amine group. Double sharp ( talk) 11:26, 26 November 2016 (UTC)
Hello fellow Wikipedians,
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It's huge -- 555 words. That's surely too long. I don't have the interest or expertise, but hope someone else does. 60.248.185.19 ( talk) 05:16, 1 June 2018 (UTC)
I'm not sure how or where to put it, but some explanation of how d-amino acids interact with multi-cellular biochemistry should be included. I have found various references to "d-amino acids are toxic to humans" on the internet, but none of them explain how. The sources I have found that say that are mostly abstracts for biochemical papers, so I assume they know what they are talking about. Nevertheless, this article does not even contain the statement "D-amino acids are toxic to most life" or its converse "d-amino acids are benign to most life". 66.219.236.172 ( talk) 07:11, 8 July 2018 (UTC)
This is entirely new to me (editing wikipedia). The section heading "D-amino acid natural abundance" is badly out of date. I recommend consulting a recent review article, Genchi, Giuseppe 2017. An overview on D-amino acids. Amino Acids, 49(9), pp.1521-1533.
https://link.springer.com/article/10.1007/s00726-017-2459-5
It is open to the public and is very good. — Preceding unsigned comment added by Gary S. Hurd ( talk • contribs) 18:31, 28 July 2019 (UTC)
Some Human Genetic Disorders Affecting Amino Acid Catabolism is a recently created subsection with a table, under Catabolism. Is it possible that the table was copied verbatim from the reference: Jain, J. L. Fundamentals of biochemistry. New Delhi: S. Chand and Co. ISBN 8121903432. OCLC 818809626. David notMD ( talk) 09:24, 25 September 2019 (UTC)
May I suggest this improved version of the first sentence in the second paragraph that begins,'In biochemistry, amino acids having both the amine and the carboxylic acid groups attached to the first (alpha-) carbon atom have particular importance.'
In biochemistry, because amino acids have both the amine and carboxylic acid groups attached to the first (alph-) carbon atom they have particular importance.
Or better still,
Amino acids have both the amine and carboxylic acid groups attached to the first (alph-) carbon atom making them particularly importance in biochemistry.
I am not game to edit things directly, but a lot of Science articles are less well written than they could be. We live in a shockingly polarised world where people stream their education and end up either Literate or Numerate, but rarely both.
Of course, the second Paragraph begins with essentially the same content as the first, which is very poetic, but extends the article making it daunting to read. Yet it is of such fundamental importance. We are mostly made of two things and this is about one of them. There is so much to think about on so many levels and in so many dimensions. See!! I am not reading it now.
NaumTered 22:18, 28 August 2020 (UTC) — Preceding unsigned comment added by Norm Tered ( talk • contribs)
In the lead, in the sentence, "In the form of proteins, amino acid residues form the second-largest component...", would it be ok to link the whole term ' amino acid residues' (as I have done here) to the specific sub-section in the chemistry article which does eventually explain 'residue' in a biochemical/protein context, instead of as it is currently, which just links the single word ' residues' to the whole chemistry article about residues in general? That article starts by giving a more general definition of 'residue', which general definition could initially be confusing to some. Further on down in that article is the relevant sub-section which defines residue in a more protein-relevant manner, and that's what I would think to link directly to. UnderEducatedGeezer ( talk) 04:36, 28 December 2020 (UTC)
The amino acid in the main figure had D configuration. This might be confusing for some readers as mostly L-amino acids are used in biology, industry, research etc. I myself tried to figure if the stereoisomer I drew is in the correct configuration by comparing to that image. Luckily I compared also with other sources. 185.175.34.246 ( talk) 12:03, 13 June 2021 (UTC)
{{ping User:Smokefoot, User:Smokefoot, User:DMacks}} There are a great many things to be corrected in this article and I plan to do some serious editing in the next few days or weeks. I'm mentioning it here because some experts will disagree with my edits, and I want to give them the opportunity to say so. Ideally, many of the figures should be redrawn, but I'm not sure that I have the skill for that. Athel cb ( talk) 09:18, 15 September 2021 (UTC)
Stimulated by the question above about toxicity of D-amino acids I have been searching for a reliable source of information. I have located my Merck Index, but it does not include systematic information about that. Likewise the Rubber Book and two encyclopaedias of biochemistry that I have. I have searched Web of Science for "LD-50" AND "amino acid" and similar search strings, but although I get vast numbers of hits I haven't found anything useful. Yet there has to be a table somewhere on LD-50 values. Any suggestions? Athel cb ( talk) 13:29, 21 September 2021 (UTC)
In the figure for cationic side-chains, the fixed cation on the arginine side chain should read H2N+= rather than H3N+=. Citation: Wikipedia's own Arginine entry, among many others. — Preceding unsigned comment added by 99.165.76.203 ( talk) 14:44, 9 November 2021 (UTC)
Beginning at the second paragraph, there's a fairly editorial description of UIPAC naming convention that puts too much weight on the rarity of the structure in nature. Especially the word "fictitious," use of scare quotes, and repeating part of a probably unnecessary quote. Same bias seems to affect the caption. This may be an important issue, but deserves at most a brief mention in the lead. At least that's how it struck me. Yellowdesk60 ( talk) 17:43, 2 January 2022 (UTC)
I quote:
Isn't that an immediate contradiction? How could "the first few" amino acids have been discovered in the "early 1900s" when several were discovered in the previous century? -- 123.243.244.238 ( talk) 10:24, 3 March 2022 (UTC)
At certain points, the article becomes unusually passionate about this notion that the names "aspartic acid" and "glutamic acid" are incorrect (see the "Anionic side-chains" subsection) and that the only correct names are "aspartate" and "glutamate". It currrently says about the acid names: "Although the misnomer is so widespread as to be ineradicable, they should not be called acidic amino acids, because they act as Brønsted bases in all circumstances except for enzymes like pepsin that act in environments of very low pH like the mammalian stomach." (bold/italic emphasis already there in the article)
I'd like the opinion of other (bio)chemists on this. I call this overly pedantic. I want to point out that this choice is inconsistent with the names of their corresponding Wikipedia pages (currently Aspartic acid and Glutamic acid), and that the acid names are used regularly in the primary and secondary literature by (bio)chemists themselves without controversy. Also, many students are likely to encounter the acid names in their first exposures. We do not emphasize that "amino acids" are "ammonium carboxylates" at all physiological pH values or that "arginine" is "argininium", and I think these would be similarly correct-yet-too-pedantic changes to make.
In the meantime, I will edit the tone to be less aggressively "anti-acid" because I think it does not contribute to the helpfulness of the article more than a neutral discussion of nomenclature would. TungstenEinsteinium ( talk) 18:30, 2 May 2022 (UTC)
This sentence is outdated. Some sources there are actually 22 [1] [2] amino acids which participate in in-vivo protein synthesis, listed below:
{{
cite journal}}
: CS1 maint: url-status (
link)
— CrafterNova [ TALK ] [ CONT ] 17:23, 7 May 2022 (UTC)
I think it may be good to add at least very brief info from/about this study and/or similar articles to the article. It's currently featured in 2022 in science like so:
Scientists report the discovery of chemical reactions by potential primordial soup components that produced amino acids and may be part of the origin of life on Earth. [1] [2]
More generally and beyond this study in specific, please add some info about how amino acids are thought to relate to the origin of life on Earth ( abiogenesis) and are thought to originate, including with some brief info in the lead. I find it strange that this seems to be entirely missing in the article if I haven't only overlooked it.
Useful sources for this may include: " Amino acids and the origin of life on Earth", " The origin of the biologically coded amino acids", " Undefining life's biochemistry: implications for abiogenesis" and " Small Cofactors May Assist Protein Emergence from RNA World: Clues from RNA-Protein Complexes".
References
Prototyperspective ( talk) 17:16, 2 September 2022 (UTC)
The diagram shows histadine without a charge on its side chain, but it is lumped in with Group A. Conversely, selenocysteine is shown with a charge on its side chain and yet is *not* in Group A. I would like to know why, and I think a lot of readers would. Also, I'd like to know what "Special Cases" (defining Group C) means. How about clarification regarding this in the caption to the diagram? Polar Apposite ( talk) 10:12, 15 November 2022 (UTC)
I edited the aliphatic side-chains section. I added "therefore" to "do not ionize", reversed the positions of isoleucine and leucine to match the General Structure chart, and added phenylalanine. I am a layman so I would appreciate a chemist checking my work here. Polar Apposite ( talk) 17:29, 17 November 2022 (UTC)
It says, "The water-soluble proteins tend to have their hydrophobic residues (Leu, Ile, Val, Phe, and Trp) buried in the middle of the protein, whereas hydrophilic side chains are exposed to the aqueous solvent." 1. Shouldn't the full names rather than the three-letter symbols be used? 2. Can a residue with a hydrophobic side chain not be hydrophobic? If so, is like being compared to like when a list of residues is contrasted with a type of side chain? 3. Is it the hydrophobic side chain that tends to be buried in the middle of the protein, or the whole residue? 4. The diagram near the top of the article lists *eight* hydrophobic (with a hydrophobic side chain, if that's different) amino acids, so is that list of five correct? Polar Apposite ( talk) 18:15, 19 December 2022 (UTC)
It says in the caption to the color chart,"The 21 proteinogenic α-amino acids found in eukaryotes, grouped according to their side chains' pKa values and charges carried at physiological pH (7.4)" but the pKa values of most of the side chains of the alpha-amino acids are not shown, and it very much looks to me that they are grouped according to hydrophobicity, and so on, as it says in the chart and ordered according to increasing complexity going from left to right, at least in the section containing the eight amino acids classified as having a hydrophobic side chain. Furthermore, in the few cases where the pKa value of the side chain is shown, there is no grouping according pKa value that I can see. Arg, His, and Lys are in the one group but the pKa value of the side chain is 12.10, 6.04, 10.67 respectively, while Tyr, which has a side chain pKa of 10.10, which would seem to indicate that it should be grouped with those three is instead in another group. Polar Apposite ( talk) 16:55, 10 January 2023 (UTC)
The following section was removed because it did not appear to fit in with the main theme, amino acids, but maybe I am mistaken:
Dietary exposure to the nonstandard amino acid BMAA has been linked to human neurodegenerative diseases, including ALS. [1] [2]
-- Smokefoot ( talk) 18:15, 29 September 2023 (UTC)
References
The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
Because of an overload of chemistry articles at GAR, if delisting, do not close before 1 March.
Looks like there's some amounts of uncited material including
Most of side chains looks uncited but I think citation 6 is supposed to be one large general reference. Though I'm not sure. Either way, the things above will need to be cited. Onegreatjoke ( talk) 22:15, 8 February 2023 (UTC)