Temperature on Enzyme Activity
We collected data on temperature on lactase activity and hypothesized temperature will have an effect on lactase activity. If temperature effect the enzyme, then lactase activity will increase. There will be 2 trials occurring with a solution created with a lactaid pill and phosphate buffer at 0, 23, 37, and 60 degrees Celsius. Every 15 seconds for 5 minutes the absorbance will be measured by ONPG solution in a spectrophotometer. There is evidence of a temperature increase at 37 and 60 degrees Celsius, but not at 0 and 23 degrees Celsius
Lactose is a sugar that is composed of monosaccharides galactose and glucose. The enzyme lactase is what catalyzes the splitting of disaccharide lactose into those two simple sugars. Lactose is important for providing energy to the human body. Also, temperature is capable of causing an effect on the body in numerous ways. In a recent study, it is determined that the effects of low water temperature on enzyme activity enhanced liver glycolytic capacity among Tilapia (Qiang et al 2014). A similar study also concluded that the effects of temperature on lactase activity enhances the carbohydrate digestion in the small intestines (Amiri & Naim 2017)
This experiment is to determine if there is a correlation between temperature and lactase activity. In order to determine an effect, the substance ONPG will change the measured substance yellow. If it is concluded that temperature has an effect on lactase activity the substance will turn yellow. If temperature has an effect on enzyme activity, then the lactase activity will increase.
To test the hypothesis an increase in temperature will increase lactase activity. My group crushed a lactaid pill, using a mortar and pestle, and combined the powder with 10 mL of 0.1M phosphate buffer into a small beaker. After 1-2 minutes, the substance dissolved and we filtered the enzyme solution, using a paper towel, into a new beaker. The dilution of 1/1000th was prepared by adding 1.5mL of stock solution with a 13.5mL of phosphate buffer. Then, we transferred 1.5mL of the solution from tube 1 to tube 2 and added 13.5mL of phosphate buffer and transferred 1.5mL of solution from tube 2 to tube 3 and added 13.5mL of phosphate buffer. Once tube 3 was prepared, 3mL of solution from that tube went into 4 cuvettes.
We repeated the steps previously stated for each temperature range and ran two trials. After we placed each cuvette into a 0 degree Celsius ice bath for 5 minutes, we added 1.5mL of 2.5nM of ONPG and place the cuvette into a spectrophotometer, at 420, to measure the absorbance. Every 15 seconds for 5 minutes a group member kept record of the measurements. We ran two trials at the temperatures 0 degree Celsius, 23 degrees Celsius, 37 degrees Celsius, and 60 degrees Celsius.
The results demonstrated in Figure 1 and Figure 2 rejects the null hypothesis at 37 degrees Celsius and 60 degrees Celsius, but failed to reject the null hypothesis at 0 degree Celsius and 23 degrees Celsius.
This experiment is determining if temperature has an effect on enzyme activity. Thus, if the increase in temperature has an effect on enzyme activity, then lactase activity will increase. The results showed there is a significant difference in enzyme activity among the temperatures at 37 degrees and 60 degrees. However, there is no significant difference in among the temperatures at 0 degrees and 23 degrees. In fact, a similar study examined core body temperature and concluded that it does not impact enzyme inhibition (Veltmeijer et al, 2017). An error in the experiment is time. The time it took removing the cuvettes from the ice bath and placing them into spectrophotometer varied. If this experiment would be conducted again, more trials and implementing temperatures that are cooler than 0 degree Celsius and warmer than 60 degrees Celsius would provide more accurate results. If temperature does have an effect on lactase activity what other enzymes could temperature effect? If temperature is capable of having an impact on other enzymes, then it is likely to inhibit the enzyme maltase.
Amiri, M., & Naim, H. Y. (2017). Characterization of Mucosal Disaccharidases from Human Intestine.Â Nutrients,Â 1-8.
Qiang, J., He, J., Yang, H., Wang, H., Kpundeh, M., Xu, P., & Zhu, Z. (2014). Temperature modulates hepatic carbohydrate metabolic enzyme activity and gene expression in juvenile GIFT tilapia (Oreochromis niloticus) fed a carbohydrate-enriched diet.Â Journal Of Thermal Biology, 25-31.
Veltmeijer, M. W., Veeneman, D., Bongers, C. W., Netea, M. G., van der Meer, J. W., Eijsvogels, T. H., & Hopman, M. E. (2017). The impact of central and peripheral cyclooxygenase enzyme inhibition on exercise-induced elevations in core body temperature.Â International Journal Of Sports Physiology & Performance, 662-667.
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