Carbohydrates-The Fuel SourceTuesday, October 27th, 2009
Carbohydrates or watered carbons are the fuel source that provides the body with ATP ( Adenosine Triphosphate). Every cell in the body uses ATP to provide power for the bodies metabolic activities. In the cell the mitochondrion breaks down glucose molecules and transforms the energy that is stored in glucose into ATP. The energy that is stored in the high energy phosphate bonds is then transfered to the organelles within the cell that do the work of the cell. What is left after the transfer of energy from the phosphate bond is a molecule of ADP or ( Adenosine Diphosphate) which can be broken down further and the remaining high energy phosphate bond can be used by the cells as a energy source. What is left is AMP or ( Adenosine Monophosphate) . Carbohydrates are classified according to size; monosaccharides, disaccharides and polysaccharides. Two monosaccharides joined together through dehydration synthesis is called a disaccharide and many monosaccharides joined together through dehydration synthesis is a polysaccharide. Monosaccharides are either hexose or pentose sugars meaning that they either have a six carbon or five carbon structure respectively. The monosaccharides; glucose, fructose, and galactose are hexose monosaccharides and deoxyribose and ribose are the common pentose sugars used by the body. Ribose and deoxyribose are important sugars found in our DNA. Sucrose, maltose and lactose are the primary disaccharides that the body uses. Sucrose is made up of the monosaccharides glucose and fructose joined together, maltose is made up of two glucose molecules joined together and lactose is made up of galactose and glucose joined together. The polysaccharide glycogen is made up of many monosaccharides joined together and is the primary energy storage carbohydrate. When the animal gets more carbohydrates then it uses in its diet these carbohydrates are joined together in the liver and transported through the blood for storage between muscle cells or remain in the liver where they will be broken back down into glucose when blood sugar levels drop. The disaccharide molecules that the animal consumes in its diet come from plant sugars like beet sugar, cane sugar, fruit sugars and milk sugars. The disaccharides are to large to pass through the cells of the lining of the intestine and must be broken down through hydrolysis with the assistance of an enzyme into simple sugars (monosaccharides). Polysaccharides that are polymers of simple sugars that the plant produces by dehydration synthesis are starches that the plant uses as a storage molecule and these large sugar molecules must also be broken down by hydrolysis with the aid of enzymes into simple sugars that can cross the intestinal cells membranes. Starches in the animals diet come from potatoes and grains that contain large amounts of starches. What is hydrolysis and dehydration synthesis? Hydro- means water and -lysis means to split apart or break down. Synthesis means to build up or combine together. So hydrolysis is to spit apart compounds or molecules by adding a water molecule and dehydration synthesis which is the opposite of this process is to join two molecules together by removing a water molecule. Both of these processes use an enzyme to assist in this process. Enzymes are globular proteins that act as catalysts. Catalysts are substances that regulate and accelerate the rate of biochemical reactions but are not used up or changed by these reactions. Each enzyme is made up of a protein part and a cofactor that can be a metal element or an organic molecule like a B complex vitamin. Each enzyme in the body is specifically formed to work with only one substrate ( the substance that any enzyme interacts with). In the next blog we will look at the important roles of enzymes in the body and the sources of carbohydrates commonly found in the animals diet.