Carbohydrate

static/images/sugar_salt.jpg

Sugar and salt crystals.

A carbohydrate is a large biological molecule, or macromolecule, that consists of carbon, hydrogen_, and oxygen atoms, usually with a hydrogen:oxygen atom ratio of 2:1 (as in water). For example, glucose, fructose_, galactose_, sucrose, maltose_, lactose_, starch, and `dietary fiber`_.

In food science and in many informal contexts, the term carbohydrate often means any food that is particularly rich in the complex carbohydrate starch (such as cereals, bread, and pasta) or simple carbohydrates, such as sugar (found in candy, jams, and desserts).

Contents

1   Function

Carbohydrates perform numerous roles in living organisms. Polysaccharides serve for the storage of energy (e.g., starch and glycogen), and as structural components (e.g., cellulose in plants and chitin in arthropods).

In the body, carbohydrate’s role is primarily energetic, that is it provides energy (through breakdown) in various tissues of the body. Most tissues in the body can use glucose for fuel and, quite in fact, most will use glucose if it is available (they will switch to using fats or ketones if glucose is not available in sufficient amounts). A few tissues of the body can only use glucose for fuel. [1]

2   Applications

When it comes to gearing up for workout, carbs are your gym BFF. The key is to have a mixed bag of complex and simple ones so that the release of energy during your workout is slow and steady throughout your routine.

3   Classification

The carbohydrates (saccharides) are divided into four chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. In general, the monosaccharides and disaccharides, which are smaller (lower molecular weight) carbohydrates, are commonly referred to as sugars.[6] The word saccharide comes from the Greek word σάκχαρον (sákkharon), meaning "sugar." While the scientific nomenclature of carbohydrates is complex, the names of the monosaccharides and disaccharides very often end in the suffix -ose. For example, grape sugar is the monosaccharide glucose, cane sugar is the disaccharide sucrose, and milk sugar is the disaccharide lactose.

Nutritionists often refer to carbohydrates as either simple or complex. However, the exact distinction between these groups can be ambiguous. The term complex carbohydrate was first used in the U.S. Senate Select Committee on Nutrition and Human Needs publication Dietary Goals for the United States (1977) where it was intended to distinguish sugars from other carbohydrates (which were perceived to be nutritionally superior). However, the report put "fruit, vegetables and whole-grains" in the complex carbohydrate column, despite the fact that these may contain sugars as well as polysaccharides. This confusion persists as today some nutritionists use the term complex carbohydrate to refer to any sort of digestible saccharide present in a whole food, where fiber, vitamins and minerals are also found (as opposed to processed carbohydrates, which provide calories but few other nutrients). The standard usage, however, is to classify carbohydrates chemically: simple if they are sugars (monosaccharides and disaccharides) and complex if they are polysaccharides (or oligosaccharides)

In any case, the simple vs. complex chemical distinction has little value for determining the nutritional quality of carbohydrates.[30] Some simple carbohydrates (e.g. fructose) raise blood glucose slowly, while some complex carbohydrates (starches), especially if processed, raise blood sugar rapidly. The speed of digestion is determined by a variety of factors including which other nutrients are consumed with the carbohydrate, how the food is prepared, individual differences in metabolism, and the chemistry of the carbohydrate.

The glycemic index (GI) and glycemic load concepts have been developed to characterize food behavior during human digestion. They rank carbohydrate-rich foods based on the rapidity and magnitude of their effect on blood glucose levels. Glycemic index is a measure of how quickly food glucose is absorbed, while glycemic load is a measure of the total absorbable glucose in foods. The insulin index is a similar, more recent classification method that ranks foods based on their effects on blood insulin levels, which are caused by glucose (or starch) and some amino acids in food.

3.1   Simple

Simple carbohydrates are sugars. All simple carbohydrates are made of just one or two sugar molecules. They are the quickest source of energy, as they are very rapidly digested.

3.2   Complex

Complex carbohydrates may be referred to as dietary starch and are made of sugar molecules strung together like a necklace or branched like a coil. They are often rich in fiber, thus satisfying and health promoting.

4   Nutrition

Carbohydrate consumed in food yields 3.87 calories of energy per gram for simple sugars,[16] and 3.57 to 4.12 calories per gram for complex carbohydrate in most other foods. High levels of carbohydrate are often associated with highly processed foods or refined foods made from plants, including sweets, cookies and candy, table sugar, honey, soft drinks, breads and crackers, jams and fruit products, pastas and breakfast cereals. Lower amounts of carbohydrate are usually associated with unrefined foods, including beans, tubers, rice, and unrefined fruit.[18] Foods from animal carcass have the lowest carbohydrate, but milk does contain lactose.

Organisms typically cannot metabolize all types of carbohydrate to yield energy. Glucose is a nearly universal and accessible source of calories. Many organisms also have the ability to metabolize other monosaccharides and disaccharides but glucose is often metabolized first.

5   Storage

Carbohydrates can be stored within the body in the liver or muscle as glycogen (a long chain of glucose molecules bonded to each other) and is found in small amounts (~5-10 grams total) as free glucose in the bloodstream. Liver glycogen exists primarily to help maintain blood glucose levels while glycogen within skeletal muscle can only be used by the muscle that it’s stored in; it can’t be released back into the bloodstream. [1]

6   Further reading

7   References

[1](1, 2) Lyle McDonald. A Primer on Nutrition. http://www.bodyrecomposition.com/nutrition/a-primer-on-nutrition-part-1.html/

Sugar does not go bad because honey is almost completley sugar. The high sugar concentration dehydrates any cells that try to take up resides through osmosis. If there's water inside of a cell that falls into the honey, the honey will pull water out of the cell until the proportion of water to sugar inside the cell is equal. Since honey has so much sugar, it pulls out nearly all of the water killing the cell.

Honey will not pass its abilities onto you by drinking it since you dilute it with your saliva.

Honey can expire if it has too much water in it, which it can pull from the air if it is stored improperly. Bees will actually cap the honey comb when the moisture of the honey gets too high (around 16-17%) so it cannot absorb any more water.

Honey, if stored properly (dry and airtight), can last thousands of years because of its sugar content and natural antibacterial properties. It will often crystallize when stored for a long time, but this does not mean the honey is bad. Simply warm it and it will turn back to honey.

Civilizations as far back as the ancient Sumerians know that honey helps treat wounds. It prevents bacteria and moisture from entering while at the same time, sucks moisture out of the wound.

Eating local honey also can help immunize against local allergies. As an informal study from Xavier University in New Orleans found, bees gather small amounts of pollen that could normally trigger allergies.2 But eating that honey introduces tiny amounts into you, and allows your immune system to build up tolerance to common allergens.

The positive aspects of honey continue. The National Journal of Biological Sciences research suggest that honey may be a great tool in the management of diabetes. Honey raises your blood sugar much less, and requires much less insulin to break down then the sugar found in most foods.


Certain things are not in fact sweet, but are highly associated with "sweet" in our culture - and thus when we smell them, we smell "sweet." Vanilla, cocoa, cinnamon are great examples: not one of these is sweet. Put them on your tongue and they're all bitter. Put them under your nose: do you smell sugar? But a huge swath of western cooking only uses these things in sweets, and so we've drawn that association.


A typical starch is a polymer of glucose units chained together, and must first be "unlinked" by enzymes (glycoside hydrolases), at which point the single units (monosaccharides) can be absorbed. Foods with smaller units need less "unlinking" and can be absorbed more quickly.