Grt1 Task2
Enzymes, ATP, Hereditary Fructose Intolerance
WGU
Role of enzymes in processes
The role of an enzyme is to catalyze a chemical reaction. Usually an enzyme increases the rate of speed of a reaction. Enzymes break down molecules in our body faster than they would normally break down without enzymes. Enzymes work at specific temperatures and pH levels. (Wolfe, 2000). For example, a stomach enzyme works better in a more acidic environment, whereas intestinal enzymes work better in a more alkaline environment. The shape of an enzyme is important to its function. Enzymes function like a lock and key. The substrate binds to the active site of the enzyme like a key into a lock. The enzyme breaks the bonds of the substrate and releases it without being consumed in the process. Substrates can also function as inhibitors, competing for the active site. (Wolfe, 2000). Sometimes one enzyme will work on one particular substrate, in other circumstances, such as with fructose, two or more enzymes work to break down a substrate so that it can be used by the body. Fructose is first broken down into fructose 1 phosphate by the enzyme fructokinase. Then fructose 1 phosphate is further broken down into dihydroxyacetone phosphate (DHAP) and glyceraldehyde by the enzyme aldolase b. (Hudon-Miller, 2012). At this point, DHAP and glyceraldehyde enter the glycolysis cycle where they can be further processed into ATP, the body’s main source of energy.
Deficiency in aldolase b Aldolase b is the enzyme which breaks down fructose 1 phosphate into DHAP and glyceraldehyde. Hereditary fructose intolerance (HFI) is an autosomal recessive disorder caused by a deficiency of aldolase b. HFI causes fructose 1 phosphate to build up in the liver, kidneys, and small intestines. This build up is toxic and leads to death of organ tissues over time. Symptoms of HFI include severe abdominal pain, vomiting, hypoglycemia, and a dislike for sweets. (Coffee &
WGU
Role of enzymes in processes
The role of an enzyme is to catalyze a chemical reaction. Usually an enzyme increases the rate of speed of a reaction. Enzymes break down molecules in our body faster than they would normally break down without enzymes. Enzymes work at specific temperatures and pH levels. (Wolfe, 2000). For example, a stomach enzyme works better in a more acidic environment, whereas intestinal enzymes work better in a more alkaline environment. The shape of an enzyme is important to its function. Enzymes function like a lock and key. The substrate binds to the active site of the enzyme like a key into a lock. The enzyme breaks the bonds of the substrate and releases it without being consumed in the process. Substrates can also function as inhibitors, competing for the active site. (Wolfe, 2000). Sometimes one enzyme will work on one particular substrate, in other circumstances, such as with fructose, two or more enzymes work to break down a substrate so that it can be used by the body. Fructose is first broken down into fructose 1 phosphate by the enzyme fructokinase. Then fructose 1 phosphate is further broken down into dihydroxyacetone phosphate (DHAP) and glyceraldehyde by the enzyme aldolase b. (Hudon-Miller, 2012). At this point, DHAP and glyceraldehyde enter the glycolysis cycle where they can be further processed into ATP, the body’s main source of energy.
Deficiency in aldolase b Aldolase b is the enzyme which breaks down fructose 1 phosphate into DHAP and glyceraldehyde. Hereditary fructose intolerance (HFI) is an autosomal recessive disorder caused by a deficiency of aldolase b. HFI causes fructose 1 phosphate to build up in the liver, kidneys, and small intestines. This build up is toxic and leads to death of organ tissues over time. Symptoms of HFI include severe abdominal pain, vomiting, hypoglycemia, and a dislike for sweets. (Coffee &
References: Coffee, E. & Tolan, D. (2010). Mutations in the promoter region of the aldolase b gene that Cause hereditary fructose intolerance Crane, F. (2001). Biochemical functions of coenzyme Q10. Journal of American College of Nutrition, 20 (6) 591-598 Hudon-Miller, S. (2012). Metabolism. Retrieved from http://www.bit.ly/grt_metabolism_nov Illingworth, J Wolfe, G. (2000). Thinkwell Biochemistry. Retrieved from http://www.thinkwell.com