Talk:Carbohydrate

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 $C_5O_4H_10$ 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 $C_5O_5H_(10)$. 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.

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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.

Inappropriate picture/caption

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..

Contradiction

Carbohydrate#Metabolism currently has one tag that says "This section requires expansion" and another tag that says "This section duplicates, in whole or part, the scope of other article(s) or section(s)". Um, well, these aren't these contradictory - if it's duplicating other material surely it doesn't need expansion, or if it needs expanding then it can't already be duplicating other material. Seems someone's not thinking about the tags they're using. --jjron (talk) 00:04, 28 April 2011 (UTC)

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:

• http://www.linksnorth.com/nutrition/nutrients.html
• http://web.nmsu.edu/~johtaylo/Nutrition1.htm
• http://www.unh.edu/health-services/ohep/pdf/GeneralNutrition/CarbohydrateIsAnEssentialNutrientFINAL.pdf
• http://health.asiaone.com/Health/Health%2BMatters/Story/A1Story20110523-280254.html
• 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)

None of these articles you quote are medical journals, just opinions and cheap talk. To anyone who wants to repair this article, links 10 and 11 are identical. — Preceding unsigned comment added by 124.184.76.92 (talk) 11:56, 17 November 2011 (UTC)

carbohydrates

carbohydrates are of three types: 1-monosaccharides 2-disaccharides 3-polysaccharides they contain carbon,oxygenand hydrogen elements — Preceding unsigned comment added by 2.89.73.70 (talk) 11:08, 17 November 2011 (UTC)