Carbohydrate refers to organic molecules that contain only carbon hydrogen
and oxygen atoms and moreover the ratio of of hydrogen to oxygen atoms is
two-to-one (the same as water{H2O}) making the basic chemical formula for
carbohydrate the following: C(H2O). In this sense, carbohydrate appears to
be "hydrated (watered) carbon"--hence the name.


Simple sugars like glucose (blood sugar) are the smallest carbohydrates and
they form the basic units or building-blocks of larger carbohydrates like
starches and cellulose. A more precise term for simple sugars is
"monosaccharide". Two-sugar carbohydrates like sucrose (table sugar) are still
technically "sugars" or, again more precisely, "di-saccharides".


"Oligosaccharides" are typically defined as chains of between three and ten
sugars and tend to be a sort of hybrid molecule with some of the properties of
sugar and some of starch. Oligosaccharides are not a common household food
and may be rather unfamiliar to people, but some examples of oligosaccharides
include stachyose (the stuff that makes beans 'gassy') and some of the
carbohydrate in malt sugar, especially "maltotriose"- a trisaccharide.
Interestingly, a tetra(four)-saccharide called "acarbose" is also an approved
drug for the treatment of type-2 diabetes because it is not only indigestible
but also blocks the effects of an oligosaccharide-digesting enzyme called
alpha-glucosidase therebye rendering much of the starch in a meal indigestible
to humans. This effect of acarbose is useful since it dramatically lowers the
glycemic load of a meal. The only problem with this effect of acarbose is that
undigested starch will pass to the colon wherein bacteria can digest it
resulting in gas. Acarbose is a class of compounds that are also known as
"starch blockers".


"polysaccharides" are chains longer than ten sugars and are familiar to most
people as simply "starch".

Carbohydrate Digestion

The human small intestine can only absorb simple sugars like glucose. Every
other kind of carbohydrate from table sugar to potato starch must first be
digested by enzymes that eventually break the carbohydrate down entirely
into simple sugars.

Carbohydrate Metabolism

Carbohydrate metabolism, like nearly all metabolism, is extremely complex and
far beyond the scope of this website. Still, several points should be stressed.

-Carbohydrate is the only macronutrient that is not essential for human life. In
the total absence of dietary carbohydrate, the body produces ketone bodies
to keep the brain alive and manages to actually make glucose from certain
amino acids and from glycerol that is liberated from triglycerides. This process
of glucose synthesis is called "gluconeogenesis" and is discussed elsewhere.

-Carbohydrate that circulates in the blood is always in the form of a
monosaccharide and by far the most prevalent of these monosaccharides is
glucose or "blood sugar".

-Increasing levels of blood glucose trigger the pancreas in healthy people to
secrete the hormone "insulin" which causes muscle and other tissue to absorb
glucose from the blood and therebye maintain glucose levels within a limited

-The disease of "diabetes mellitus" is named for the fact that it causes people
to have sweet tasting urine (this truly was an ancient way of diagnosing the
disease and the sweet flavor is due to the presence of large amounts of
glucose in the urine caused by extremely high blood glucose levels.

-Diabetes mellitus is the name given to two totally different diseases that
happen to both share the feature of very high blood glucose levels.

-Type-1 diabetes is also called "childhood-onset" diabetes, tends to strike
children and young adults, tends to develop extremely rapidly(often within
weeks) and is usually very serious and hard to control from the outset. Nearly
all patients with type 1 diabetes are insulin dependant. Type-1 diabetes is
caused by a failure of the pancreas to produce insulin due to the sudden
death of all or nearly all of its insulin-producing cells. Most scientists believe
that type 1 diabetes is caused by a virus although the causitive agent is not

-Type-2 diabetes is also called "adult-onset" diabetes and tends to develop in
adults. Type-2 diabetes usually develops slowly and worsen slowly over years.
Type-2 diabetes is caused not by a lack of insulin production from the
pancreas, but rather by insulin resistance. Among the strongest risk factors
for type-2 diabetes are obesity, metabolic syndrome, family history and early
indications of insulin resistance like rising glyco-hemoglobin (HbA1C) levels.
Type-2 diabetes presents in varying degrees of severity: some people can
control it just by reducing sugar and carbohydrate in their meals, many
patients achieve good control through the use of one or a combination of
several oral medications while some type-2 diabetics require insulin injection.
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