In the healthcare perspective, according to Gennaro et al. (2000), biochemical reactions are the chemical reactions involved in biochemical and cellular processes and particular actions of substances that affect these processes. Understanding biochemical reactions lead to the “understanding of the molecular bases of diseases”. The knowledge of receptor sites and metabolism (among other things) direct healthcare measures in efficient therapy management. Knowing normal cellular communication and metabolic pattern chemical reactions determine conditions that are abnormal in disease states. To Giese (2013), the scope of pharmaceutical reactions involve those of pharmaceutical biomolecules and biomolecule analogues and the chemical reactions involving those that the body does to the drug and the chemical reactions that the drug undergoes to effect the body. These concepts guide the rationale behind how and why medications work and don’t work, and their implications on interactions (food, drug, etc.), side effects, toxicology, etc. Young (1988) summarized that diagnostic reactions are used in instrumentation and diagnostic tests involving chemical reactions of biomolecules and reagents to predict body states, determine abnormal conditions, and detect diseases.
A specific example for a biochemical reaction would be the hydrolysis of glucose-6-phosphate. Glucose-6-phosphatase catalyzes this reaction to create a phosphate group and glucose. This reaction fulfills the terminal step in gluconeogenesis and glycogenolysis and is important in regulating blood glucose levels. Chou, Jun and Mansfield (2010) showed in their study that it is vital for healthcare professionals because the lack of the enzyme or mutation in the enzyme system that triggers this reaction results to glycogen storing problems and eventually leads to abnormalities in glucose regulation, neutrophil function and homeostasis. Edwards (1950) studied the “hydrolytic cleavage of aspirin to salicylic acid and acetic acid”. This pharmaceutical reaction is important to note as it is the reason why aspirin is highly unstable in aqueous solutions. What happens is that instead of a general acid-base hydrolysis, because of the presence of an orthocarboxylate anion, aspirin dissociates in the solution prior to administration, rendering the drug less effective since only a portion of it is available for metabolism. This knowledge is significant to the healthcare professional so as to find another delivery system that would make the drug more stable. A common example for a diagnostic chemical reaction would be how the Breathalyzer works. It estimates the blood alcohol content of an individual by employing a visible color change upon the reaction of alcohol from a person’s breath upon contact with a chemical mixture into the breathing device. The relevance of this is that knowing the chemical reaction, one will know the approximate level of alcohol in a person by just basing on the color changes predicted by the chemical reaction.
An example of a balanced biochemical equation would be this: G6P + H2O = Glu + Pi. This is the hydrolysis equation for glucose-6-phosphate. This is the important step that signals glycogen storing and blood glucose level regulating. This is the hydrolysis reaction of aspirin: C9H8O4 + H20 = C7H6O3 + C2H4O2. In aqueous solutions, it is catalyzed and breaks down into salicylic acid and acetic acid rendering the drug preparation ineffective. For the diagnostic reaction of the Breathalyzer, this is the equation: 2Cr2O72- + 3C2H5OH + 16H+ → 4Cr3+ + 3C2H3O2H + 11H2O. When ethanol enters the breath analyzer, it reacts with the dichromate ion in the solution. The dichromate ion becomes converted to chromium ion. As the dichromate ion is converted to chromium ion, the color changes from orange to blue green. The degree of the change in color is indicative of the level of alcohol in one’s breath.
According to Knozinger and Kochloefl (2002), catalysts are either homogeneous or heterogeneous. A homogeneous catalyst exists in the same phase as the reactant or the substrate. A heterogeneous catalyst, on the other hand, exists in a different phase than the reactants. A catalyst in the human body is called an enzyme. An example of this would be phenylalanine hydroxylase which is responsible for catalyzing the hydroxylation of phenylalanine’s aromatic side chain to generate tyrosine. It is the “rate-limiting enzyme of the metabolic pathway that degrades excess phenylalanine” (Kaufman, 1958). Mutations in phenylalanine hydroxylase leads to a severe metabolic disorder called phenylketonuria. Phenylketonurics develop disturbances in the motor system. Also their hair, skin, and eyes develop light coloration. Mental retardation is also an effect of this metabolic disorder especially with those born without the enzyme.
Enzymes bond with substrates to form “transition states” or unstable intermediates as alternative pathway to proceed to reactions that require less energy. These chemical reactions include oxidation-reduction reactions catalyzed by oxidoreductases, chemical group transfer catalyzed by transferases, hydrolytic reactions catalyzed by hydrolases, group addition to double bonds or vice versa catalyzed by lyases, rearrangement of molecules catalyzed by isomerases, and condensation of molecules alongside the cleavage of phosphate bonds catalyzed by ligases (or synthetases).
References
Chou, J.Y., Jun, H.S., and Mansfield, B.C. (2010). Glycogen storage disease type I and G6Pase-ß deficiency: etiology and therapy. Nat Rev Endocrinol, 6 (12): 676-88. doi:10.1038/nrendo.2010.189
Gennaro, A.R., Der Marderosian, A.H., Hanson, G.R., Medwick, T., Popovich, N.G., Schnaare, R.L.,White, H.S. (2000). Remington: The Science and Practice of Pharmacy. Philadelphia: University of Science in Philadelphia.
Giese, R. (2013). Biochem. Retrieved from http://youtu.be/UmGilNRX_3A
Kaufman, S. (1958). A new cofactor required for the enzymatic conversion of phenylalanine to tyrosine. Journal of Biological Chemistry, 230 (2): 931-9. Retrieved from http://ncbi.nlm.nih.gov/pubmed/13525410
Knozinger, H., Kochloefl, K. (2002). Heterogeneous catalysis and solid catalysts. Ullmann’s Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a05_313
Young, F.E. (1988). Self-Care: Self-Medication in America’s Future. Washington DC: The Proprietory Association.
