How Metabolism Lead to Health and Sickness - Essay Example

How Metabolism Lead to Health and Sickness According to Glew and Rosenthal p metabolism is the given to the sequences of biochemical reactions that degrade, synthesize, or interconvert small molecules inside living cells.” The understanding of the metabolic pathways, as well as their interactions, enhances one to understand the normal function, as well as metabolic basis of many human diseases. Metabolism always takes place in small discrete steps in assistance of enzymes, catalysts. In relation to this, one can define a metabolic pathway as a particular set of reactions that do certain functions. Examples of metabolic pathways include gluconeogenesis that maintains the concentration of glucose in the body at the required level and tricarboxylic acid (TCA) cycle, which is associated with oxidizing the two carbons of acetyl-coenzyme A to CO2 and water, enhancing the completion of the catabolism of carbohydrates, fats, and proteins (Glew & Rosenthal 2011). The metabolism of molecules inside cells often leads to good health. However, metabolic disorders result in diseases. In relation to this, the paper aims at expounding on how metabolism leads to health, as well as sickness. In aggressing this, the paper will detail on different metabolic pathways, their essence to health, and how their metabolic complications results in diseases. Bile Acid Synthesis Metabolism of cholesterol to bile acids that take place in the liver serves two purposes: it provides bile salts to the intestines that facilitate fat digestion and absorption through their emulsifying properties. Secondly, metabolism of cholesterol to bile acids is one way of getting rid with excess cholesterol. Humans lack the ability of breaking open any of the rings of cholesterol. Additionally, humans cannot oxidize cholesterol to carbon dioxide and water. It is as a result of this that excretion of cholesterol as bile salts, as well as cholesterol per se, is considered the only mechanism the body gets rid of significant quantities of cholesterol. The cytoplasmic thiolase enzyme that is involved in the biosynthesis of cholesterol may fail to carry out its functions because of some abnormalities. Such failures, unfortunately, lead to accumulation of lipids to vital organs of the body resulting in disorders referred to as lipidosis. Other enzyme abnormalities may also bar the body from converting fats to energy, fatty acid oxidation disorders. Some of the diseases that result from disorders of lipid metabolism include Gaucher’s disease, Tay-Sachs disease, Niemann-Pick disease, and Fabry’s disease. Gaucher’s disease results from the accumulation of glucocerebrosides which are products of fat metabolism. This disease is the most common lipidosis. It results in not only an enlarged liver and spleen, but also a brownish pigmentation of the skin. The clumping of glucocerebrosides in the eyes causes pingueculae also referred to as yellow spots. Tay-Sachs disease is also a metabolism disease that is caused by the accumulation of gangliosides, products of fat metabolism, in tissues (Abdel-Aleem & Lowe 1998). The disease is associated with intellectual disabling as well as appearance of floppy muscle tone in children at very early age. The disease also leads to the development of spasticity that is followed by paralysis, dementia, as well as blindness. The disease has no cure, and as a result it cause death. Niemann-Pick disease is associated with the accumulation sphingomyelin that is a product of metabolism in the tissues (Merck Mannuals 2015). In severe form (type A), the disease prevents children from growing normally. Type B disease is associated with the development of fatty growths in the skin, presentation of areas of dark pigmentation, hepatomegaly, splenomegaly, and lymph nodes. Fabry’s disease is also caused by the accumulation of glycolipid (a product of fat metabolism) in tissues. The buildup of glycolipid causes noncancerous skin growths to form on the lower part of the trunk. Glucose synthesis Metabolism of carbohydrates involves breaking down of simple sugars (sucrose and lactose) and complex sugars into their simple constitutes by enzymes so that the body can manage to utilize them. Disorders of enzymes required to process the sugars lead to accumulation of the sugar in the body, resulting in metabolism diseases (Harkness, Pollitt & Addison 1990). Thus, metabolism of carbohydrates is important; it helps maintain the required level of sugar in the body. Deficiency of enzymes associated with metabolism of certain sugars results in diseases such as glycogen storage disease, galactosemia, hereditary fructose intolerance, mucopolysaccharidoses, and disorders of pyruvate metabolism. Glycogen storage diseases occur when metabolism of glycogen fails because of a defect in specific enzymes. This disease also results from a lack of an enzyme responsible for the conversion of glucose into glycogen, as well as the breakdown of glycogen into glucose. This type of a metabolic defect results in growth abnormalities, weakness as well as confusion. Galactosemia is also a metabolic disease that is caused by the absence of an enzyme required in metabolizing galactose. This disease is associated with the accumulation of a metabolic that is toxic not only to the liver, but also the kidneys (Masells & Mazza 2009). The built up of the metabolite damages the lens of the eyes resulting in cataracts. Hereditary fructose intolerance is also a metabolism disease that is caused by the absence of the enzyme required to metabolize fructose. Very small amount results in low blood sugar levels that may lead to liver and kidney damage (Hon Dossier 2004). The failure of fructose metabolism leads to accumulation of a by-product of fructose in the body which blocks the formation of glycogen, as well as its conversion to glucose. Amino acids synthesize Metabolism of proteins is a process that is associated with breaking down dietary proteins into amino acids so that they can be absorbed into the bloodstream. The absorbed amino acids are then used to either synthesize new proteins or as energy source (Institute of Medicine 1999). Metabolism of proteins is also associated with converting to some protein to glucose via gluconeogenesis (Welle 1999). The disorder of enzyme associated with the breakdown of proteins into amino acid results to protein metabolism diseases such as phenylketonuria, maple syrup urine disease, homocystinuria, and tyrosinemia. Phenylketonuria (PKU) occurs as a result of lack of the enzyme responsible for converting the phenylalanine to tyrosine. The metabolism disorder results in the accumulation of the amino acid phenylalanine in the blood causing intellectual disability. Maple syrup urine disease is also a metabolism disease that is caused by lack of a specific enzyme associated with the metabolizing amino acids (Wintour & Owens 2006). Severe form of this disease results in infants developing neurologic abnormalities in addition to seizures and coma. Disorder of the enzyme associated with the breakdown of proteins may also lead to the occurrence of homocystinuria (Hoffmann, Zscocke & Nyhan 2009). This disease is caused by the absence of the enzyme required to metabolize homocysteine. In severe condition, the disease results in behavioral disorders as well as intellectual disability. Failure of the breakdown of tyrosine also results in a metabolism disease referred to as tyrosinemia. In conclusion, metabolism is essential in humans. It aids in the breakdown of simple and complex materials into forms that can be utilized by the body. Nutrients are the common compounds that undergo the process of metabolism in the body. Carbohydrates, for instance, are broken down into simple sugars that are utilized by the body or converted into glycogen for storage. Cholesterol, on the other hand, is broken down with the aid of the enzymes into bile acids that are utilized by the body. Just as carbohydrates and cholesterol, proteins are also broken down by the aid of specific enzymes to amino acids that are utilized by the body to form proteins or glucose through the process gluconeogenesis. The failure or absence of the enzymes associated with the metabolism process leads to occurrence of metabolism diseases such as Gaucher’s disease, Tay-Sachs disease, Niemann-Pick disease, and Fabry’s disease in case failure of cholesterol metabolism. Phenylketonuria, maple syrup urine disease, homocystinuria, and tyrosinemia also occur because of the failure of protein metabolism. Additionally, glycogen storage disease, galactosemia, hereditary fructose intolerance, mucopolysaccharidoses, and disorders of pyruvate metabolism occur because of complications with carbohydrates metabolism. Reference List ABDEL-ALEEM, S., & LOWE, J. E. (1998). Cardiac metabolism in health and disease. Dordrecht, Kluwer Academic Publishers. HARKNESS, R. A., POLLITT, R. J., & ADDISON, G. M. (1990). Carbohydrate and Glycoprotein Metabolism ; Maternal Phenylketonuria. Dordrecht, Springer Netherlands. http://dx.doi.org/10.1007/978-94-009-2175-7. HOFFMANN, G. F., ZSCHOCKE, J., & NYHAN, W. L. (2009). Inherited metabolic diseases a clinical approach. Heidelberg, Springer. http://dx.doi.org/10.1007/978-3-540-74723-9. Hon Dossier. (2004). Carbohydrate Metabolism Disorders. http://www.hon.ch/Dossier/MotherChild/child_metabolism/metabolism_carbohydrate.ht ml INSTITUTE OF MEDICINE (U.S.). (1999). The role of protein and amino acids in sustaining and enhancing performance. Washington, D.C., National Academy Press. http://search.ebscohost.com/login.aspx?direct=true&scope=site&db=nlebk&db=nlabk&A N=11720. MASELLA, R., & MAZZA, G. (2009). Glutathione and sulfur amino acids in human health and disease. Hoboken, N.J., John Wiley. http://public.eblib.com/choice/publicfullrecord.aspx?p=455914. Merck Manuals. (2015). Disorders of Lipid Metabolism. http://www.merckmanuals.com/home/childrens_health_issues/hereditary_metabolic_diso rders/disorders_of_lipid_metabolism.html ROSENTHAL, M. D., & GLEW, R. H. (2009). Medical biochemistry: human metabolism in health and disease. Hoboken, NJ, John Wiley & Sons. WELLE, S. (1999). Human protein metabolism. New York, Springer. WINTOUR, E. M., & OWENS, J. A. (2006). Early life origins of health and disease. Springer E-Books. New York, N.Y., Springer Science+Business Media. http://public.eblib.com/choice/publicfullrecord.aspx?p=371717. Read More