Enzymes are proteins that are catalysts for biological processes. The enzymes can slow down or speed up a biological reaction. Enzymes have an active site, which have different shapes for different functions it is to perform. A reaction will begin when a substrate with the matching shape connects to the enzyme. It is critical that these pieces correctly fit together in order for the process to run smoothly and complete its job. Enzymes help break up large molecules faster than if there were no enzymes, thus releasing energy into the body faster. One very important enzyme in the human body is aldolase B, it is responsible for the metabolizing fructose.
Fructose is a naturally occurring monosaccharide in the body. Fructose often bonds with sucrose and becomes what most people know as table sugar, which is a disaccharide. (United States National Library of Medicine, 2011). Before fructose is broken down to be used as energy, is it converted to fructose-1-phosphate. As mentioned earlier, aldolase B is needed to break down fructose in the human body. If there is a deficiency of aldolase B, a person will experience Hereditary Fructose Intolerance (HFI)
HFI is an autosomal recessive trait that is related to a mutation of the ALDOB gene (USNLM, 2011). This gene is responsible for making the aldolase B enzyme. The mutated gene causes the aldolase B enzyme to be misshaped, unable to function properly. When a person ingests fructose, it is converted to fructose-1-phosphate. After this conversion, fructose-1-phosphate should be metabolized into aldoase B. When there is a deficiency in aldolase B, the fructose is signaled by the fructose kinase to keep making fructose-1-phosphate. Along with this deficiency, fructose-1-phosohate is no longer being used as a substrate to make the products DHP and glycol aldehyde, which allows even more fructose-1-phosphate to continue to stay in the cell. This buildup of phosphate (Pi) in the cells from the aldose B deficiency will deplete the free phosphate pools in the cells. ADP uses the phosphate pools in the cells to make ATP, but with the depleted natural Pi, the electron transport chain cannot work properly and ATP production slows. Slow ATP production will cause the liver cells to have less energy eventually causing liver failure. The fructose-1-phosphate also signals high blood sugar. While it is building up in the cell, it is telling the glucokinase to stay in the cytoplasm of the cell and the amount of glucose released into the bloodstream is reduced causing hypoglycemia. People with HFI are usually asymptomatic until they ingest sorbitol, sucrose or fructose. Treatment for HFI is usually dietary restrictions. If untreated, HFI can eventually lead to hypoglycemia, jaundice and kidney failure.
cell membrane. This releases energy that is used to form ATP. Co-enzyme Q10 is synthesized by the body and can enter the body through dietary intake.
