What knowledge have you connected with past knowledge?

There have been many examples of connections between what we are learning in biochemistry and what we have learned in other disciplines. In general chemistry we learned about the rate equation and in biochemistry we can apply it to reactions that occur within the cell. In organic chemistry we learned about functional groups and in biochemistry we are able to recognize those functional groups in amino acids and the importance of how structure determines function. In biology we studied the organelles of a cell and in biochemistry we examine the chemical reactions that occur within the organelles. In physics we studied kinetics and in biochemistry we are able to relate kinetics to reactions that occur within the cell.

In biochemistry we recently discussed the functions of enzymes and the enzyme deficient disease that comes to mind is Lactose Intolerance. The intolerance is caused from an over abundance of lactose (milk products) and a deficiency in lactase enzyme to bind with the substrate to catalyze the breakdown of the milk. People who are lactose intolerant are not able to produce the necessary lactase to keep up with the abundance of substrate. In these cases the rate of the reaction is zero order because the concentration of the substrate is so high that the enzyme is completely saturated with reactant molecules. (Campbell, p. 147) Without the catalyst the lactose remains in the intestine and ferments. This causes a production of gas that is painful and uncomfortable. In biochemistry we learned that enzymes can bind, catalyze and are released to bind again with another substrate. This may explain why some adults continue to drink milk without any ill effects. Studies have shown that adult mammals normally have a 90 to 95 percent reduction in birth lactase levels. (Swagerty, 2002) This suggests that lactase deficiencies are normal and that people who are able to tolerate large amounts of milk products are abnormal. As an infant or young child it is necessary to have large quantities of milk products making it necessary for the body to produce large amounts of enzyme to digest them. Once the body has matured the need for milk products is decreased and the need for enzyme to digest it decreases as well. In people that continue to intake large amounts of milk products, there is likely a message that is sent to continue to produce the enzyme. Since the body is likely to have a significant reduction in enzyme production it is required to reuse the enzymes over and over to keep up with the demand for a catalyst.



Reference:
• Campbell, Mark K., Farrell, Shawn O. (2008), Biochemistry, sixth edition
• National Digestive Disease Information Clearinghouse (June 2009), retrieved 2/25/2010 from: http://digestive.niddk.nih.gov/ddiseases/pubs/lactoseintolerance/
• Swagerty, Daniel L. JR., M.D., M.P.H., Walling, Anne D. M.D., and Klein, Robert M. PH.D. (May 2002), American Academy of Family Physicians, retrieved 2/25/2010 from: http://www.aafp.org/afp/2002/0501/p1845.html