Talk:Carbohydrate
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I think we need a citation for the statement '1 carbohydrate molecule will make you gain 27 pounds'. It looks suspiciously like vandalism to me.
[edit] 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 C5O4H10 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 C5O5H(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 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.
[edit] "Carbs" boom
I expected there to be information on the sudden boom of "low-carb" diets in this article. Why isn't there? --Antoshi 20:19, 5 February 2006 (UTC)
Most likely because it does not have to do directly with information of Carbs, such as structure and uses, but you could probably add a link to it under the "see also" section. Matt White 23:42, 15 February 2006 (UTC)
[edit] Good article nomination
This article looks like it meets all the criteria, except that the section 'catabolism' doesn't really mean much at the moment, and needs to be expanded. Worldtraveller 10:47, 12 March 2006 (UTC)
[edit] Gigantic and totally unexplained contradiction
"Strictly speaking, carbohydrates are not necessary for human nutrition because proteins can be converted to carbohydrates. The traditional diet of some cultures consists of very little carbohydrate, and these people remain relatively healthy. ... Very low carbohydrate diets can slow down brain and neural function because the nervous system especially relies on glucose." How could both of these statements possibly be true? If someone knows anything about this, go ahead and fix it and don't focus on responding to me, because I'm probably going to forget about this. Tyharvey313
Well technically one could be very stupid and yet perfectly healthy. Servingsper 06:25, 17 April 2006 (UTC)
[edit] 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..
[edit] Refined Carbohydrates
An explanation of what refined carbohydrates are has not been provided and does not exist elsewhere. I can't seem to find an in-depth explanation of this on the net so far... --MatthewKarlsen but edit as 81.86.122.174 (talk • contribs)
[edit] Definition of "complex carbohydrate"
I'm not sure exactly what this term means. Sometimes it seems like carbohydrates are always caloric foods (starch, sugar, etc.) and that thus they all have the same calories per gram. Other times it seems like "complex carbohydrates" includes some fiber (or is entirely fiber) which implies it should have a lower calories per gram than simple carbohydrates. I can't tell if fiber is really a carb or not. Boris B 11:32, 27 November 2006 (UTC)
"Breads, pastas, beans, potatoes, bran, rice and cereals are all high in carbohydrates." This is doubtless true, but these all seem to be low (or moderate?) in simple carbohydrate content. Was this sentence written with a definition of carbohydrate which doesn't include sugars, or could the sentence be modified to include candy, dessert pastries, and many sodas? I'm just fumbling toward a consistent working definition of "carbohydrate" here (i.e. including sugars or not, including fiber or not). Boris B 19:50, 27 November 2006 (UTC)
- The article certainly does not clarify the definitions of complex carbohydrates well. In answer to some of your specific questions, sugars, starches, and fiber are all definitely carbohydrates. There is no ambiguity there (although in some circles the term is used in non-technical ways to excluded fiber or other types of carbohydrates).
- The term complex carbohydrate, to the extent that I have seen, is used in all of the following senses.
- 1) Any carbohydrate other than simple sugars.
- 2) Fiber
- 3) A group of carbohydrates that includes fiber (e.g. if a slice of bread has a lot of fiber in addition to the starch it is often said to have only complex carbohydrates whereas white bread does not).
- 4) Any carbohydrate or group of carbohydrates that has a low glycemic index (although how low depends on the source).
- I believe in scientific discussion the first one would be considered the most "proper" definition although it is common for doctors to use the other definitions in many settings. The reason for the lack of clarity, as I understand it, is that at one time doctors believed that simple sugars were the only "bad" carbohydrates, so "complex carbohydrates" (which include starch and fiber) came to be synonymous with "good carbohydrates." Now it is recognized that some starches can be as bad or worse than sugar so, rather than admit they were wrong, some doctors and nutritionists have quietly altered how they use the term to fit the original intention of what they were trying to describe.
- --Mcorazao 17:40, 5 December 2006 (UTC)
[edit] Necessitating the use of fat in energy production?
I have a problem with this sentence in the Nutrition section of the article: "Proteins and fat are vital building components for body tissue and cells, and thus it could be considered advisable not to deplete such resources by necessitating their use in energy production." With the latter part of it, to be specific. According to what I read on cell metabolism, cells make energy by burning sugar, fat and oxygen or - in the absence of oxygen - by burning just sugar. This latter process is (if I understood correctly) used either for very brief periods of time or merely to supplement the first process. So fat is pretty much ALWAYS used for energy. So, while the second part of the sentence makes perfect sense when we're talking about proteins, it seems like a silly thing to say about fat. Daelyn 21:24, 5 February 2007 (UTC)
- Your conclusion "So fat is pretty much ALWAYS used for energy" is false and I don't see why you think it follows from the other things you said, which I think are accurate. Fat is used to form cell membranes. Because the brain is composed of a lot of long, thin connections, a large percentage of the mass of the brain is composed of cell membrane, and the healthy functioning of these membranes is important to brain function. Deficiency of omega-3 fats can lead to mental illness -- not because these fats are sometimes used to burn energy. They're an important component of cell membranes. Fats are also used to form many other substances such as hormones and eicosanoids. Burning them for energy is only one of their uses in the body.
- The recommendation seems illogical to me: since fats are essential components of the body, to avoid necessitating their burning as energy, and therefore to eat a large percentage of carbohydrates, which cannot be used as components of the body. That seems all wrong to me. It's like saying that water is very valuable because it's so healthy so we shouldn't waste it by drinking it but should drink juice instead. It would make sense to have a minimum percentage of the diet as fats, and a minimum percentage as protein for use as a building block plus an additional percentage as either protein or carbohydrates for use as brain energy; I see no obvious need for any minimum carbohydrate intake, unless one makes the argument that using protein for energy leaves too much nitrogen to be excreted, and in that case the minimum carbohydrate intake should be just enough to provide energy for the brain -- much less than half the diet. Note Udo Erasmus' recommendations [1]; his food pyramids focus on a larger percentage of (healthy kinds of) fat, and he claims many benefits of this diet. --Coppertwig 12:38, 17 February 2007 (UTC)
[edit] Insulin index
I'm not sure that this recently added sentence is true: "This [simplistic] system assumes that high glycaemic index foods and low glycaemic index foods can be mixed to make the intake of high glycaemic foods more acceptable.". I deleted the word "simplistic" as being POV. If true, this should at least be explained more fully and supported with references on the insulin index page, and perhaps moved to that page rather than stated here. How does the amount of a food affect insulin response? Would adding a slice of bread to a piece of pie make the pie more acceptable according to this system, or would you have to replace half the piece of pie with half the slice of bread to get a benefit? --Coppertwig 12:24, 17 February 2007 (UTC)
[edit] carbohydrates as non-essential nutrients
Sorry, but carbohydrates are essential, since if you tried using only fat and/or protein for energy, you will eventually become quite sick (or worse). On paper it looks like protein has a lot of energy but in practice it's not a very efficient way to get energy. This part of the article really needs to be cleaned up because it is misinformation. By the way, Coppertwig above mentions something about "just enough carbs to power the brain". How the heck do you measure the exact amount your brain needs? Sounds like a whole lotta silliness to me.—The preceding unsigned comment was added by 207.161.43.153 (talk) 21:21, 6 March 2007 (UTC).
[edit] confused
what the? —The preceding unsigned comment was added by 217.180.11.192 (talk) 16:16, 16 March 2007 (UTC).
