Carbohydrate (of which sugars)..

[Lynnieshell]

what does this mean. Is the 'of which sugars' part the stuff that is refined and therefore hits your bloodstream quickest (as opposed to cpmplex carbohydrates.

[j2buttonsw]

Sugar is another name for carbohydrates. Carbohydrates (or CHO) is a generic term for a class of compounds which have particular structural features and functionality. Glucose is a common carbohydrate which is used by the body to produce energy, in fact most sugars are eventually broken down or converted to glucose before being used by the body. Granulated sugar should be called SUCROSE and it consists of a molecule of glucose bound to another sugar molecule called fructose. Sucrose can be easily broken down into it constituents and fructose can be converted to glucose. Complex carbohydrates are usually made up of many molecules of glucose all joined together in chains (such as starch). Because it takes the body longer to break down the chains of glucose moleclues into the individual molecules that it can use, complex carbohydrates don't have the instant effect of raising your blood sugar (glucose) level than eating glucose directly.

[darth vader]

sorry to correct you j2b - sucrose consists of two glucose molecules bound together (fructose is found in fruit). http://www.sucrose.com/ will confirm this.

Glucose is the body's energy source, Lynnieshell, carbohydrates are broken down to form glucose. The problem with sucrose is the body finds it hard to break the bond between the two glucose molecules down, so sugar usually is turned into stored fat by the body, rather than used as immediate energy sources. This is why it is best to eat carbohydrates which are low in sugars. Incidentally the jury is still out about whether the fructose in fruit is good or bad for you and most diets are usually vague about fruit consumption levels. Personally i say eat fruit and forget sweets.

[j2buttonsw]

Darth, my dad's bigger than your dad: http://www.chem.ox.ac.uk/mom/carbohydrates/sucrose
.html

[j2buttonsw]

Darth, SUCRASE is the enzyme produced by animals to break down sucrose into it's constituent parts and, as far as I am aware, it has no problems at all doing it. http://www.essaybank.co.uk/free_coursework/1920.ht
ml

[darth vader]

I think we will have to agree to disagree.

"The simplest of the sugars is glucose, C6H12O6, although its physical chemistry is not that simple because it occurs in two distinct forms which affect some of its properties. Sucrose, C12H22O11, is a disaccharide, a condensation molecule made up of two glucose molecules [less a water molecule to make the chemistry work]." (source
The target=_blank>http://www.sucrose.com/learn.html)

The Oxford Uni article you mention says "Sucrose is a disaccharide that yields 1 equiv of glucose and 1 equiv of fructose on acidic hydrolysis" - i don't know what acidic hydrolysis is, but according to this article it produces invert sugar. (Interestingly it doesn't mention carbon in it's diagram...)

I was taught by my biologist that sugar requires effort/energy to be broken down into glucose and is usually stored as fat reserves by the body; the body will turn to ready glucose supplies first.

shall we call it a draw?

[Lynnieshell]

OOps Look what I started. Scrap! scrap! scrap! scrap! In my inadequate knowldge my question was based on whether, when looking at food labels, the amount of carbs "of which sugars" should be high (to provide instant energy) or low (cos it's bad for you). I shall go and ponder all this info.... Thankyou all for your efforts

[darth vader]

tee hee - we do not fight we merely debate the answers to questions.
In relation to your final posting then my opinion is that it is better to eat carbs, which gives you a slow steady release of energy, rather than sugary (glucose) foods which release energy immediately (and possibly giving you a "sugar rush"). Having said that, if you are about to climb a mountain or go for a run then you might consider wanting an instant energy boost (and stuff a mars bar or a few dextrosol tablets down or drink some lucozade etc).
right that's it i promise not to say anything more on the subject

[j2buttonsw]

Darth, you have asked for it: In Stryer 3rd Ed 1988 (ISBN 0-7167-1843-X), a standard Biochemistry undergraduate book pp 339, sucrose is a disaccharide in which glucose is joined to fructose by an alpha 1, 2 glycosidic link. You must have found the only web page that says it is made of two glucoses (which is in fact MALTOSE). I have written to them outlining their error. Fructose is an structural isomer of glucose with the same molecular formula (C6H12O6) but is a pentose not a hexose. Glucose has many other structural isomers (galactose being another). Interestingly, fat is made up from chains of acetate molecultes (roughly speaking) so in order to make fat, complex carbohydrates are broken down into glucose then further catalysis (in the form of glycolysis) to produce acetyl CoA.

[darth vader]

I'm not giving in 'till i've seen my old Biology lecturer (which might not be easy as i left school 16 years ago) but i hear what you're saying j2b

[Andromeda]

Lynnieshell - to clarify - low sugars is better as the balance will be complex carbohydrates and therefore take more effort to break down. Complex carbohydrates in the food sense generally means starch - as in rice, flour potatoes etc. Actually I'd go for low carb, as we all tend to get too much in our diet anyway!

Andy

[Andromeda]

Boys, boys, boys. Glucose and fructose are structural isomers - glucose being a six member ring sugar (pyranose) and fructose a five member ring sugar (furanose). Sucrose - a disaccharide is made up of one each of glucose and fructose. No argument. (and where is Andy Hughes or Incitatus when you need them???)

Andy

[Andromeda]

Oh, and Jsbuttonsw - both glucose and fructose are hexoses - they have six carbons (arranged differently). Ribose (as in DNA and RNA) is a pentose. It has only 5 carbons.

Andy