The Effect of NaCl on the Reaction Rate of Catecholase Background - PowerPoint PPT Presentation

The Effect of NaCl on the Reaction Rate of Catecholase

Background Enzymes require a specific environment to function 1 ❖ Changes in salt concentration can disrupt form of non-covalent bonds 2 ❖ Block active sites ➢ Catecholase leads to browning of bruised or cut fruit 1 ❖ Enzymes react similarly to salt 3 ❖

Hypothesis and Prediction Hypothesis ★ The amount (volume) of sodium chloride has an effect on the activity of the enzyme ○ catecholase. Prediction ★ If the amount (percent) of sodium chloride has an effect on the activity of the ○ enzyme catecholase, then the tube with 20% NaCl will have a higher absorbance level at 400 nm.

Procedure 2 3 1 4 Prepare Test Blanking Initial Reading Tubes Final Reading Spectrophotometer See detailed procedure below

Constants ➢ Wavelength of 400nm ➢ Amount of NaCl used, if used ➢ Drops of catecholase used - 2 ➢ Time spent in spectrophotometer - 5 min. ➢ Time enzyme was exposed to treatment

Data table Mean of Reaction Rates Standard Deviation Control - 0% NaCl 0.0143 0.00527 IV 1 - 5% NaCl 0.0066 0.002315 IV 2 - 20% NaCl 0.0024 0.000589

Results An ANOVA test was run P-Value = 0.002 → Significant p-value Sig or not sig? Control IV1 .024 Significant IV2 .002 Significant IV1 IV2 .231 Not significant

Conclusion ● The NaCl has an effect on the enzyme, catecholase ● One possible error: not cleaning the tube before the absorbance was taken ● Future Question: how does NaCl affect other enzymes? ● How much of the Na compared to the Cl affect the enzyme activity?

Works Cited 1. University of Mary Washington Department of Biological Sciences. (n.d.). Lab Modules to Accompany BIOL 121: Observing and Investigating Biological Systems (Vol. 1). 2. "Salt Concentration Effect on Reaction Rates." UKEssays.com. 11 2013. All Answers Ltd. 10 2018 https://www.ukessays.com/essays/biology/salt-concentration-on-turnip-peroxidase-activity-biology-essay.php?vref=1 3. Greenway, H., and C. B. Osmond. “Alt Responses of Enzymes from Species Differing in Salt Tolerance.” Plant Physiology , U.S. National Library of Medicine, Feb. 1972, www.ncbi.nlm.nih.gov/pmc/articles/PMC365940/?page=3.