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Structure of monosaccarides
Am I the only one thinking the glucose and fructose molecules look wrong. They seem to be correct empirically and based on their quantities of atoms. But the structure seems is not cyclic like most monosaccharides. Look at http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Carbohydrates.html for soem ideas on how to draw these molecules properly. I can draw them myself on paper quite well, but I usually find them difficult to do accurately on computer. I might scan in a few drawings of molecules ive got lying around when I find time, if anyone can find any use for them.
Also, when you say "but many important carbohydrates, like deoxyribose have more hydrogen" you are technically wrong. The formular for ribose (if you look at the empirical formula you can see mine is consistent) is . The thing about deoxyribose is, as the name suggests, an oxygen removed. Not hydrogen atoms.
"Carbohydrates consist almost exclusively of just three elements: carbon, hydrogen, and oxygen"
When you say this, 'almost' is perhaps a bad words. ALL carbohydrates are carbon, hydrogen and oxygen always. Glycoproteins and the like are not carbohydrates, so they are exempt from this rule. Pure carbohydrates, cellulose, glycogen, fructose, maltose, etc are all made from carbon, hydrogen and oxygen.
"The binding between one of the two sugars results in the loss of a hydrogen atom H from one molecule and a hydroxyl group from the other." This is essentually correct, it is known as a condensation reaction. I would edit this myself to add but I would rather not do so at this time, perhaps someone can fix this article.
I see there is a link to the nomenclature of carbohydrates. I personally think if this information was rewritten carefully here in an easy to understand and presentable form it would be very useful. I might undertake this myself later on, as I have this page bookmarked.
Jedi Dan Thanks for listening
Carbohydrates can change between ring form and straight-chain form. Hopefully the changes I have made address most of your complaints, except for the easy to understand bit, which I'm not a good enough writer to do. It would be helpful if someone went over them.
Typically, carbohydrates are classified into the sweet sugars (monosaccharides and disaccharides) and the unsweet, starchy, polysaccharides. Monosaccharides are simple, crystalline sugars. Disaccharides are composed of two monosaccharides joined together (hence di-saccharides). Polysaccharides are very large molecules such as starch or glycogen, which are formed from many monosaccharides joined together (poly-saccharides).
The characterization of monosaccharides as sweet and crystalline, and polysaccharides as unsweet and starchy is looking at only a few well-known examples. I don't think it can be worked into something which is generally valid.
The image of very REFINED grain foods (white bread, pasta, flour, sugar are pictured) is captioned: "Unrefined grain products are rich sources of complex carbohydrates". This should be changed to a more appropriate image I think..
Is carbohydrate essential?
This report couldn't conclude either way: http://www.ajcn.org/content/75/5/951.2.full
These references call it essential:
- Discovering nutrition, Timothy Carr, Timothy P. Carr. Page 8. "The six essential nutrient classes are carbohydrates, proteins, ..."
There are a bunch that say the opposite also. Basically, we shouldn't say definitively that carbs are not an essential nutrient if the references disagree so much. Sancho 19:36, 14 June 2011 (UTC)
- Or, at least we can make clearer the distinct meaning of "essential nutrient" that we're using here. In every-day usage, carbohydrates seem to be generally considered an essential nutrient. Sancho 19:43, 14 June 2011 (UTC)
- I agree, this article suggests carbs are not necessary to our diets, when there is more studies/articles that suggest they should be part of our diets. The article is not only one sided, it's premise relies on a non-scientific 'opinion'. It needs to be revised to reflect mixed scientific opinion. — Preceding unsigned comment added by 220.127.116.11 (talk) 18:16, 14 October 2012 (UTC)
Carbs include sugars (and specifically glucose), which are essential towards producing ATP, the bodies energy source. It is noted that tapping into fats for energy, increases the risk for Ketosis. It has been argued by other sources (not included in the article) that Carbs should be an essentially part of our diet. However, the article doesn't include anything that reflects that position. — Preceding unsigned comment added by 18.104.22.168 (talk) 17:13, 19 March 2013 (UTC)
- Then provide a source for this claim and add it to the article. (You might also create a user account.) I myself have not seen any scientific source for the claim that carbohydrates are essential for humans, and some that suggest they are not. Your claim that glucose is essential for ATP production is not true and even if true is irrelevant to this article. Many cells in the human body can feed fatty acids (and other nutrients) into the Krebs cycle (or other places in respiration) directly. Also, humans can create glucose endogenously from glycerol and some amino acids. If we are creating glucose in our bodies from other nutrients, it is, by definition, not essential.
- I would like to see your sources for the claim that carbs are essential in the scientific meaning of that term.Michaplot (talk) 04:32, 3 April 2013 (UTC)
- What do you mean "risk for ketosis"? Who told you ketosis was a risk in generally healthy people? Ketoacidosis may be a risk for diabetics, but we're not all diabetics.
- Donjoe (talk) 22:25, 28 February 2014 (UTC)
carbohydrates are of three types: 1-monosaccharides 2-disaccharides 3-polysaccharides they contain carbon,oxygenand hydrogen elements — Preceding unsigned comment added by 22.214.171.124 (talk) 11:08, 17 November 2011 (UTC)
The introduction is WRONG. !!! Very.
A paraphrase of the IUPAC Definition (1996) of a generic carbohydrate is: "The term 'carbohydrate' includes monosaccharides, oligosaccharides and polysaccharides and includes compounds derived from monosaccharides by: → a) reduction of the carbonyl group (alditols), → b) by oxidation of one or more terminal groups to carboxylic acids, or → c) by replacement of one or more hydroxy group(s) by a hydrogen atom, an amino group, a thiol group or similar heteroatomic groups. It includes derivatives of these compounds. About 3% of the compounds listed by Chemical Abstracts Service ( > 360 000) are named using carbohydrate nomenclature. Note that Cyclitols are not generally regarded as carbohydrates." This DIRECTLY CONTRADICTS the lede. --- I will add that the first reference claims their formula is Cn(H2O)n and someone has changed that to the more general Cm(H2O)n and then SCREWED up the article by saying that m doesn't have to equal n. I suggest that this prototypical formula be "Cn(H2O)n' where usually n = n'." To emphasize the exception at the expense of the more useful general rule of thumb is worse than foolish.126.96.36.199 (talk) 22:23, 3 September 2013 (UTC)
- In the example of lactose which is illustrated, m=12 and n=11, i.e., they are not equal. Lactose is not an atypical carbohydrate. --Robert.Allen (talk) 01:08, 5 September 2013 (UTC)
Definition of carbohydrate as a macromolecule
Monosaccharides, disaccharides and trisaccharides are not defined as macromolecules, only polysaccharides such as starch, cellulose, pectin, alginate, chitin, etc are. — Preceding unsigned comment added by 188.8.131.52 (talk) 19:17, 9 September 2014 (UTC)