Enzymes are proteins, they act as catalysts to speed up biochemical reactions that take place within cells. They are crucial components of life on earth and serve a range of functions in the human body such as adding with metabolism and digestion (Live Science). The enzyme amylase is produced by salivary glands and pancreases of Homo Sapiens. Salivary amylase is the first amylase enzyme involved in the breakdown and digestion of starch in the oral cavity. The enzyme amylase was examined along with the amylase, alpha 1A (salivary) gene (AMY1A) that produces this enzyme. The amylase produced by the pancreas and salivary glands is also referred to as alpha-amylase as it is able to break down the alpha glyosidic linkages in polysaccharides, such as starch and glycogen, which are broken though the process of hydrolyzation (Tracey 2018). Starch is a photosynthesized polysaccharide that is found in green plants which is an energy source for most living organisms. There are two components of starch, amylose and amylopectin. Amylose is a polysaccharide composed of alpha-D-glucose units bonded to each other through alpha (1 ? 4) glycosidic linkages. Amylopectin is a larger molecule in which is composed of ?-1,4-linked glucans connect through a ?-1,6 linkage to form a highly branched structure. The crystalline structure of amylopectin is a result of the branching which occurs regularly at different regions of the molecule. Moreover, glycogen is an alpha-glucan which is found in animals and microorganism. It is composed of ?-1,4-linked glucans which is connected by the ?-1,6 linkage. The linkages occur frequently and are distributed throughout the glycogen molecule, making it soluble in water (Science Direct).
The aim of this experiment was to determine if there is an association between the enzyme production, gene copy number and gene evolution. Hence, the purpose of this experiment is to determine if the variation in the gene copy number and enzyme production is in response to the quantity of starch that one’s ancestors consumed in their diets. Due to gene duplication, extra copies of the gene are added to the genome, which results in a variation of the number AMY1A gene that an individual possesses. The selective pressures that may have acted on the individuals from populations or ancestry that consume high starch diets resulted in them having a higher average number of repeats than individuals from populations or ancestry that consume a low starch diet (Tracey 2018). According to the findings in the “Diet and the evolution of human amylase gene copy number variation” article by Perry et al. in 2007. The AMY1A gene shows a great amount of variation amongst different populations. It was concluded that the AMY1A gene copy number is positively correlated to the salivary amylase concentration. Individuals from populations with a high starch diets have more AMY1A copy genes than individuals from populations with a low starch diets (Perry et al. 2007).
The saliva of the test subjects was diluted through a process called serial dilution; a technique where series of 10-fold dilutions of the original undiluted solution are produced. This is done in order to find the optimal dilution of the results where the concentration can be calculated (Tracey 2018). The gene copy number was found using the polymerase chain reaction (PCR) which was used to amplify the target DNA, the AMY1A copy gene, in this experiment. The results of PCR were visualised through gel electrophoresis, a process in which the DNA fragments are pulled through the agarose gel, separating the DNA fragments according to their size. A picture of the gel was taken using ultraviolet lighting. The DNA fragments size was determined using a DNA base pair ladder (Morris et al. 2016).