Jump to content

Talk:Organic compound

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by 207.54.194.253 (talk) at 20:04, 20 May 2009. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

WikiProject iconChemistry Start‑class Top‑importance
WikiProject iconThis article is within the scope of WikiProject Chemistry, a collaborative effort to improve the coverage of chemistry on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
StartThis article has been rated as Start-class on Wikipedia's content assessment scale.
TopThis article has been rated as Top-importance on the project's importance scale.

useless article

This article is terrible. It starts off with a short text, and then there is a looong list of links, and then a short article with no substance. Seems that there is alot missing here. Sorry for naging. Seismic Boom 13:44, 25 September 2007 (UTC)[reply]

Could you be more specific about what you think is missing from the article? --Itub 14:07, 25 September 2007 (UTC)[reply]

What are functions, uses and examples of carbohydrates?

Read: http://en.wikipedia.org/wiki/Carbohydrates Seismic Boom 13:44, 25 September 2007 (UTC)[reply]


EPAL!! —Preceding unsigned comment added by 122.52.81.87 (talk) 03:09, 13 July 2008 (UTC)[reply]

nucleic acid

The first isolation of what we now refer to as DNA was accomplished by Johann Friedrich Miescher circa 1870. He reported finding a weakly acidic substance of unknown function in the nuclei of human white blood cells, and named this material "nuclein". A few years later, Miescher separated nuclein into protein and nucleic acid components. In the 1920's nucleic acids were found to be major components of chromosomes, small gene-carrying bodies in the nuclei of complex cells. Elemental analysis of nucleic acids showed the presence of phosphorus, in addition to the usual C, H, N & O. Unlike proteins, nucleic acids contained no sulfur. Complete hydrolysis of chromosomal nucleic acids gave inorganic phosphate, 2-deoxyribose (a previously unknown sugar) and four different heterocyclic bases (shown in the following diagram). To reflect the unusual sugar component, chromosomal nucleic acids are called deoxyribonucleic acids, abbreviated DNA. Analogous nucleic acids in which the sugar component is ribose are termed ribonucleic acids, abbreviated RNA. The acidic character of the nucleic acids was attributed to the phosphoric acid moiety.

The two monocyclic bases shown here are classified as pyrimidines, and the two bicyclic bases are purines. Each has at least one N-H site at which an organic substituent may be attached. They are all polyfunctional bases, and may exist in tautomeric forms. Base-catalyzed hydrolysis of DNA gave four nucleoside products, which proved to be N-glycosides of 2'-deoxyribose combined with the heterocyclic amines. Structures and names for these nucleosides will be displayed above by clicking on the heterocyclic base diagram. The base components are colored green, and the sugar is black. As noted in the 2'-deoxycytidine structure on the left, the numbering of the sugar carbons makes use of primed numbers to distinguish them from the heterocyclic base sites. The corresponding N-glycosides of the common sugar ribose are the building blocks of RNA, and are named adenosine, cytidine, guanosine and uridine (a thymidine analog missing the methyl group). From this evidence, nucleic acids may be formulated as alternating copolymers of phosphoric acid (P) and nucleosides (N), as shown: ~ P – N – P – N'– P – N– P – N'– P – N ~

At first the four nucleosides, distinguished by prime marks in this crude formula, were assumed to be present in equal amounts, resulting in a uniform structure, such as that of starch. However, a compound of this kind, presumably common to all organisms, was considered too simple to hold the hereditary information known to reside in the chromosomes. This view was challenged in 1944, when Oswald Avery and colleagues demonstrated that bacterial DNA was likely the genetic agent that carried information from one organism to another in a process called "transformation". He concluded that "nucleic acids must be regarded as possessing biological specificity, the chemical basis of which is as yet undetermined." Despite this finding, many scientists continued to believe that chromosomal proteins, which differ across species, between individuals, and even within a given organism, were the locus of an organism's genetic information. It should be noted that single celled organisms like bacteria do not have a well-defined nucleus. Instead, their single chromosome is associated with specific proteins in a region called a "nucleoid". Nevertheless, the DNA from bacteria has the same composition and general structure as that from multicellular organisms, including human beings.

Views about the role of DNA in inheritance changed in the late 1940's and early 1950's. By conducting a careful analysis of DNA from many sources, Erwin Chargaff found its composition to be species specific. In addition, he found that the amount of adenine (A) always equaled the amount of thymine (T), and the amount of guanine (G) always equaled the amount of cytosine (C), regardless of the DNA source. As set forth in the following table, the ratio of (A+T) to (C+G) varied from 2.70 to 0.35. The last two organisms are bacteria. Nucleoside Base Distribution in DNA


HI , NAFISAH IS KOOOOOOL =D x —Preceding unsigned comment added by 78.149.246.105 (talk) 19:03, 9 March 2009 (UTC)[reply]

carbon compounds

like common nutrients we need to eat to get

what are the characteristics of organic compounds

CF4 (tetrafluoromethane)

according to your definition, tetrafluoromethane and teflon is not an organic compound as they don't have hydrogen atom. are they inorganic or organic compound?

See the third paragraph. They are in a gray area. Some chemists consider perfluorocarbons organic, and some don't. Personally, I think they should be special add-on's, since (as noted) the C-F bond confers physical properties in some (but not all) ways resembling the C-H bond. However, if you've ever seen a flask with a high MW perfluorocarbon liquid (like perfluorooctane) on the bottom, a layer of water above that, and a layer of pure hydrocarbon like benzene on top, you see three clearly different types of immiscible fluids. If you do enough of that, you begin to consider perfluorocarbons as perhaps needing a class of their own! They are very weird compounds. [[User:Sbharris|#REDIRECT [[[Target page name][http://www.example.com link title--207.54.194.253 (talk) 20:04, 20 May 2009 (UTC)#REDIRECT Target page name]]]S]]BHarris 18:17, 3 August 2006 (UTC)[reply]

Definition of an organic compound

The general definition of organic compounds as those containinSubscript text<math>Insert non-formatted text here</math>[[Media:[[File:Example.ogg]]{| class="wikitable" border="1" |<blockquote> - ! header 1 ! header 2 ! header 3 |- | row 1, cell 1 | row 1, cell 2 | row 1, cell 3 |- | row 2, cell 1 | row 2, cell 2 | row 2, cell 3 </blockquote> |}]]g carbon-hydrogen bonds is in desperate need of revision. There are numerous instances of organic compounds that do not contain carbon-hydrogen bonds, the most pertinent of which being urea. This compound is widely known as the first organic compound to be successfully synthesized (as mentioned in the article), yet itself contains no carbon-hydrogen bonds! The gray-area of which the article speaks seems far too broad for this archaic definition to be used any longer.

Another is is the simplest dicarboxilic acid, oxalic acid HOOC-COOH. Surely organic if succinic is, since the chemistry is nearly identical. And the diamide of oxalic acid as well. And are mono and difluoroacetic acids to be considered organics, but trifluoacetic acid not? There is also a crystalline polymer HOOC-(CO)n-COOH which looks and feels awfully organic to me. There are also trifluormethyl versions of methyl methacrylate and methyl polyvinyl alcohol polymers which would be strange not to consider organic--- even odder than Teflon. So yes, I fully agree with the problem. Want to have a whack at solving it, perhaps in a subsidiary LEAD paragraph talking about a significant minority view? SBHarris 06:55, 10 September 2006 (UTC)[reply]
I have been an organic chemist for over thirty years and have never seen a definition of "organic compound" as limiting as that used in this article. I could sit here all night and list compounds which almost any organic chemist would consider to be "organic" yet which contain no hydrogen. Carbon disulfide (which is produced anerobic decomposition of biomass and would even fit the classical definition of "organic"), carbon tetrachloride, decachlorobiphenyl (a PCB), mellitic anhydride (anhydride of benzene hexacarboxylic acid) are all inorganic by the definition used in this article. One definition says that a compound is organic if an organic chemist says it is (this works for me!). However, Morrison and Boyd, in one of the most used organic chemistry texts, simply state that organic chemisty is the study of the chemistry of carbon.
I put in the Morrison and Boyd reference for you. With that authority, it deserves mention. SBHarris 04:06, 29 April 2007 (UTC)[reply]
I suggest replacing "An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic" with "An organic compound is one which contains carbon. Some simple compounds such as oxides (carbon monoxide and carbon dioxide), carbides (eg. tungsten carbide), small ionic salts (eg. cyanides, carbonates, cyanates etc) and allotropes of carbon (eg. diamond and graphite) are generally considered to be inorganic." This makes the article consistent with the one on inorganic compounds.Silverchemist 05:04, 12 February 2007 (UTC)[reply]

could somebody make a poem or song about compounds?

Four Major classes

What are the four major classes of organic compounds? —The preceding unsigned comment was added by 69.139.52.73 (talk) 15:45, 20 January 2007 (UTC). i dont know, a need help!!!!!!!! i want to know if what are those classes of orgamic compounds.[reply]

Talk pages of Wikipedia articles are for discussing improvements to articles. They are not places to request help with your homework.
I expect your question relates to biochemistry, in which case the four main classes of biomolecules are carbohydrates, lipids, proteins, and nucleic acids. I don't think this information really belongs in an article on organic chemistry - it is already covered in biochemistry and biomolecule.
Next time, use Wikipedia:Reference desk, or just read your textbook, consult your notes, ask a teacher or a classmate. Don't rely on Wikipedia talk pages, that's not their purpose!
Ben 11:18, 25 March 2007 (UTC)[reply]

Unreferenced

I added the unreferenced template at the top of the article because there is no source for the claimed definition (compounds containing C-H bonds). This is an arbitrary definition; there are others that could be used. --Itub 10:08, 6 March 2007 (UTC)[reply]

Definition of an organic compound

I apologize for the anonymous "template" posted earlier bemoaning the injustice inherent in a definition of organic chemistry whose core tenet implies a relationship lacking in its foundational constituent (and far too many others, as was pointed out). I should have prefaced it with a contextual clue as to why anyone should even care, n'est ce pas? I just think that as scientists, it is our nature to strive constantly to maintain the most stringent definitions of our respective disciplines and of ourselves as their representatives. Admittedly, I am not an organic chemist by trade, but it troubles me to witness the persistence of such an archaic and, frankly, nonsensical definition of organic compounds as those containing C-H bonds. As a graduate student in genetics, it would bother me greatly to see a gene defined as "a segment of DNA encoding a protein". While this is true for the vast majority of genes, some gene transcripts (about 8% of those in humans) are not fated for translation into proteins (such as those emanating from rRNA and tRNA genes, whose intrinsic functions in the ribosome depend upon their remaining as RNA). Such a definition would be, in my mind, far too narrow and simply false.

I was always very fond of organic chemistry, and it saddened me to think that a science with such myriad and multifaceted molecular architectures could be so narrowly defined, especially in a growing general worldwide knowledge base frequented by millions. That is why I had to add my two cents' worth. As far as arriving at a solution, I would prefer to leave that to the real experts, i.e. the organic chemists.

Eganio 01:58, 29 April 2007 (UTC)[reply]

I've updated the definition to the simpler and more accepted one of "carbon compounds minus a few traditional exceptions". I also removed the whole section about the "dispute". There is no dispute; it's just that there is no "official" definition and every textbook chooses its own wording, in ways that are not always identical. However, textbook authors with any sense always mention that the exact distinction is historical, not that important, and somewhat subjective. A good way of putting it is this one:
"Although this division into organic and inorganic is useful in organizing the vast subject of chemistry, the division is somewhat arbitrary. For example, a compound that contains both carbon and a metal, such as chlorophyll or hemoglobin, may be considered either organic or inorganic, depending on the interest of the person who is studying it. It is equally difficult (and unnecessary) to draw a line separating organic chemistry and biochemistry." Organic Chemistry By Joseph M. Hornback; Published 2006 by Thomson Brooks/Cole.
Hope this helps. --Itub 08:37, 2 May 2007 (UTC)[reply]
In January 2008 and unregistered user ignored the discussion on this page and changed the definition. I have gone back to the original, broader definition. Silverchemist (talk) 22:09, 5 April 2008 (UTC)[reply]

I was well aware of the discussion. What you call a "broader definition" is simply wrong. 87.183.98.229 (talk) 17:37, 25 May 2008 (UTC)[reply]

I have reverted you change again, 87.183.98.229. You are acting against consensus. Your definition of organic compounds (compounds with C-H bonds) is not the only accepted definition, and you have not provided a reference.
Ben (talk) 21:35, 25 May 2008 (UTC)[reply]
I wholeheartedly agree with Ben. Making a change against consensus, with no rationale or references is bad form for anyone, especially a anonymous unregistered user. Morrison and Boyd's "Organic Chemistry" 3rd edition (one of the standard texts for university level chemistry courses) begins "Organic chemistry is the chemistry of compounds of carbon". Silverchemist (talk) 23:20, 25 May 2008 (UTC)[reply]

"An organic compound is any member of a large class of chemical compounds whose molecules contain carbon." This is the opening sentence in the article and it is false. Later qualifications are contradictory to this statement, and it should be removed. Also, it should be noted that in most major undergraduate and graduate level text books on organic chemistry define organic compounds as those compounds containing a C-H bond. Urea is not "organic" (contrary to the Urea article) and HCN is. Both of these articles(on organic compounds and carbon compounds that are inorganic) are in need of major revisions. I would suggest that this article be cleaned up by providing multiple definitions, the history behind them, and their pros and cons. The definition of what is organic in 1828 is not the same as the definitions we use today. It is no longer something produced by an organism, because we now know that we can make these compounds from inorganic starting materials and that organism produce plenty of inorganic compounds, sometimes from organic compounds. The entire C-H definition was adopted as a way to simplify things, as there are no exceptions. Endtothemeans (talk) 04:55, 7 June 2008 (UTC)[reply]

Show us some reliable references that state explicitly that urea is not organic and HCN is. I would also be interested in seeing that majority of texbooks you refer to. --Itub (talk) 07:05, 7 June 2008 (UTC)[reply]
Apart from Morrison and Boyd's standard text book (see above), there are almost 150 websites (most of them hosted by universities) which contain the sentence "Organic chemistry is the chemistry of compounds of carbon" (try a Google search with the quotation marks in place and omit "Adams" to avoid unnecessary duplication due to one much cited quotation). Cotton and Wilkinson in Advanced Inorganic Chemistry: a Comprehensive Text say "There are more known compounds of carbon than of any other element except hydrogen, most of them best regarded as organic chemicals." Websters New World Dictionary 2nd ed. defines "organic" (sense 4) as "designating or of any chemical compound containing carbon: some simple compounds of carbon, such as carbon dioxide are frequently classified as inorganic".
The simplistic C-H requirement for an organic chemical leads to some ludicrous situations. For example in the reaction sequence CH2=CH2 --> CH2CL=CH2CL --> CCl2=CCl2 --> CHCl2-CCl2F the carbon-containing material is organic, organic, inorganic and then organic again. Also, PTFE (Teflon) would be inorganic while Tefzel ETFE would be an organic polymer, even though both are fluoropolymers. Including hydrogen cyanide as an organic compound raises another issue since that C-H bond is very much more polar (almost to the extent of being ionic) than a normal covalent C-H bond. Simplicity doesn't imply accuracy. The exclusive, no exceptions allowed, C-H definition creates more problems than it solves. Silverchemist (talk) 04:37, 8 June 2008 (UTC)[reply]
What I was taught is that a compound is considered organic if it contains at least one C-C or C-H covalent bond. That would resolve the problems you show above since the C-C bonds would mean that all these compounds are organic. Indianopilot (talk) 20:11, 16 March 2009 (UTC)[reply]
Any arbitrary declaration would "resolve the problem", but "I heard it somewhere" is a totally invalid reason for accepting one from among the various ideas. DMacks (talk) 20:15, 16 March 2009 (UTC)[reply]