Carbohydrates

//A Guide to the World of Carbohydrates by Michelle. E. Flohr & Gabby //

//What is a Carbohydrate? //  It is a LARGE biological molecule that consists of //**Carbon, Hydrogen, and Oxygen**//. Carbohydrates perform numerous roles in living organisms. Polysaccharides serve for the storage of energy, and as structural components (e.g., cellulose in plants and chitin in arthropods).

5-carbon monosaccharide ribose is an important component of coenzymes and the backbone of the genetic molecule known as RNA.

The related deoxyribose is a component of DNA. Saccharides and their derivatives include many other important biomolecules that play key roles in the immune system, fertilization, preventing pathogenesis, blood clotting, and development.

Many carbohydrates are large polymers composed of repeating units of simple sugars.



=// Types of Carbohydrates //= They can be characterized as... -Monosaccharides   Which are known as the simple sugars, the most basic type of carbohydrates that have multiple -OH groups. Mono meaning "one" and saccharide meaning "sugar". Each has a cyclic structure. The ratios of carbon, hydrogen and oxygen are **1:2:1** Depending on the number of carbons that they have, a monosaccharide can be either **TRIOSE, TETROSE, PENTOSE, or HEXOSE.** They are the building blocks of Disaccharides. **EXAMPLES: Glucose, Fructose and Galactose**.

-Disaccharides  It is the carbohydrate that is formed when two monosaccharides undergo a condensation reaction.

This involvesthe elimination of a small molecule, such as water, from the functional groups only.

This process is known as the **"dehydration reaction"**

Like monosaccharides, disaccharides form an aqueous solution when dissolved in water.

The glycosidic bond can be formed between any hydroxyl group on the component monosaccharide.

So, even if both component sugars are the same, different bond combinations (regiochemistry) and stereochemistry (alpha- or beta-) result in disaccharides that are diastereoisomers with different chemical and physical properties.

Depending on the **__[|monosaccharide]__** constituents, disaccharides are sometimes crystalline, sometimes water-soluble, and sometimes sweet-tasting and sticky-feeling.



EXAMPLES: **SUCROSE, LACTOSE, and MALTOSE**

-Polysaccharides  Polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic bonds. They range in structure from linear to highly branched.

Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. They are combined in a reaction that is known as the "**condensation reaction"**

Nutrition polysaccharides are common sources of energy. Many organisms can easily break down starches into glucose, however, most organisms cannot metabolize cellulose or other polysaccharides like chintin and arabinoxylans.These carbohydrates types can be metabolized by some bacteria and protists. Ruminantsand terminates, for example, use microorganisms to process cellulose.



And this includes sugars, starches and cellulose.



=//Functions of Carbohydrates in Regards to Human Biochemistry //= Carbohydrates have four basic functions.
 * <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif; font-size: 110%;">Source of energy
 * <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif; font-size: 110%;">Sparing protein
 * <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif; font-size: 110%;">Assisting fat oxidization
 * <span style="font-family: 'Trebuchet MS',Helvetica,sans-serif; font-size: 110%;">Role in gastro-intestinal function

=**Carbohydrates as a Source of Energy**=

The function of storing energy is one of the greatest and most central functions of the carbohydrate. More than 50-80% of energy in the human diet is supplied by carbohydrates. Some carbohydrates may be used up immediately by the tissues, whereas other carbohydrates (or whatever is left over) will be stored as glycogen in the liver and muscles. Some carbohydrates may also be stored as adipose tissues for energy needs in the future.

=Carbohydrates Sparing Protein=

Through the ability for carbohydrates to store energy, proteins are spared. Because of this proteins are allowed to focus on tissue building and repairing. The biggest physiological need of the human body is the need for energy. This need MUST be satisfied before nutrients can be used for other functions. Because of this, even though it seems like this isn't a major function of a carbohydrate it is really important. The proteins are allowed to contribute to their primary purpose of body building and repair of tissue instead of settling energy needs.

=Carbohydrates Help Oxidize Fat=

Carbohydrates are absolutely necessary in the oxidation of fats. In fact, without carbohydrates, fats cannot be oxidized by the body at all. No energy will be yielded. This is all due to a breakdown product of carbohydrates called oxalacetic acid. Oxalacetic acid is essential for the oxidation of acetate, otherwise known as the breakdown product of fats. If there is no oxaloacetic acid, the acetate (fats) are converted into ketone bodies. Ketone bodies can build up in the body and can form a toxic condition named 'Ketosis." Ketosis generally occurs when a) People who have diabetes, when the cells are not able to utilize carbohydrates, and b) In starvation, when cells are forced to use fat deposits in the body as their source of energy.

= = =Carbohydrates Have a Role in Gastro-Intestinal Function=

Carbohydrates have a big role in the gastro-intestinal functions and processes within mammals. There are desirable bacteria in the small intestine that bring about the synthesis of particular B-complex Vitamins. Lactose not only promotes the growth of these bacteria but also enhances the absorption of calcium. Additionally, Cellulose provides bulk and fiber to help in the stimulation of the peristaltic movements of the gastroinal tract.

=//<span style="background-color: #ffffff; font-family: Georgia,serif; font-size: 25px;">Health Problems/Conditions Related to Carbohydrates //=
 * Constipation and Diverticulosis
 * Irritable Bowel Syndrome
 * Obesity
 * Crohn's Disease
 * Haemorrhoids

=Constipation and Diverticulosis= Low fibre diets can lead to constipation because the stool is too hard to pass at a regular rate. Pressure that's applied to try to move the stool out can cause bulges to form in weak places of the colon and causes abdominal pain. This is known as diverticulosis. Diverticulosis is very common in the western world because the diet has too much processed food in it, and not enough fibre.

=Irritable Bowel Syndrome= Irritable bowel syndrome refers to any symptoms that arise from the bowel not functioning properly. Some symptoms include; constipation, bloating, and abdominal pain. Eating a high fibre diet can help decrease the symptoms of irritable bowel syndrome.

=Obesity= Obesity is caused my excess eating. Obesity can lead to cardiovascular disease, diabetes, difficulty breathing and sleeping etc. A high fibre diet makes the consumer feel more full on less food which leads to weight loss.

=Crohn's Disease= Chron's disease is an inflammatory bowel disease of the large intestine or the lower part of the small intestine. The cause of this disease is completely unknown. However, dietary fibre can help in the prevention of this disease.

=Haemorrhoids= This conditions can be caused by constipation or obesity, and entails enlarged blood vessels in and around the rectum and anus causing discomfort and bleeding. A high fibre diet helps constipation and therefore risk of haemorrhoids.

= =//<span style="background-color: #ffffff; font-family: Georgia,serif; font-size: 140%;">Questions/Quizes on Carbohydrates //= <span style="background-color: #ffffff; font-family: Georgia,serif; font-size: 140%;">Quiz on Carbohydrates: http://www.softschools.com/quizzes/language_arts/carbohydrates/quiz2612.html

= =//<span style="background-color: #ffffff; font-family: Georgia,serif; font-size: 25px;">Sources //= http://www.preservearticles.com/201105146671/5-most-essential-functions-of-carbohydrates.html http://woman.thenest.com/DM-Resize/photos.demandstudios.com/getty/article/138/25/sb10067958fe-001.jpg%3Fw%3D600%26h%3D600%26keep_ratio%3D1 http://vitaflexlifestyle.com/files/2012/06/carbohydrates.jpg http://www.scribd.com/doc/87000750/14/B-4-2-Outline-the-di%EF%AC%80erence-between-HDL-and