Lactase Lab

Introduction: Lactase is an enzyme that helps to digest lactose, a sugar found in many dairy products (U.S National Library of Medicine 2013). This enzyme is made through instructions provided by the LCT gene. Lactase is primarily produced and found in the cells that line the walls of the small intestine. At the brush border, an area where microvilli absorb nutrients from food as it passes by, lactose breaks down lactose into simpler sugars like glucose through a hydrolysis reaction (Biology 225 Lab Manual 2016). However in the years after being breast-fed, which provides an infant with an abundance of lactose, the typical mammalian diet does not consist of a lot of lactose (Alberts, Bray, Hopkins, et al. 294 2014). This leads to a low activity of lactase, which consequences in the enzyme being down-regulated. This results in mammals, including 70% of …show more content…
Lactase persistence is the result of a gene mutation and therefore considered the mutant allele while non-persistent is the wild-type allele. However, the LCT gene itself is not mutated. The single base pair mutation (a change from a “C” to a “T”) occurs in an intron of a neighboring gene that lies 13,910 nucleotides upstream, which alters the process in which the LCT gene is turned on and off (Biology 225 Lab Manual 2016). This mutated DNA complex interacts with another protein to alter expression of the LCT promoter (Cross and Terrill 2015). This mutation is most common amongst non-Hispanic whites/Europeans. The objective of the lab is to determine whether each whether each individual in a set of 60 individuals is lactase persistent or lactase non-persistent. Furthermore, it was also determined if those individuals who are lactase persistent are homozygous or heterozygous for the LCT