LABORATORY 12-MEASUREMENT OF ENZYME ACTIVITY-DAY 2
BIOL 105-LAB 12-Exercise 1
EFFECT OF pH
- Record data from video in the table below.
- Determine the concentration of p-nitrophenol in each “E” tube by using the standard curve that was generated in Exercise 1 (Day 1 lab). Record this concentration.
| pH | Absorption at 410nm | Concentration of pNItrophenol |
| pH 3.0 | 0.0100 | 1 |
| pH 4.8 | 0.0134 | 2 |
| pH 7.0 | 0.0185 | 3 |
| pH 9.0 | 0.034 | 4 |
Discussion Questions for Exercise 1
- How did the pH affect the level of enzyme activity?
Every enzyme has an optimum range of pH within which it operates. A change in the pH outside such a range results in slowing of the activity of the enzyme. Very high values might results in denaturing of the enzyme (Li et al., 2020). The change in the pH as well resulted in a change in the shape of the active site of the enzyme
- What was physically taking place to the enzyme at each level of pH?
There is a change in the concentration of substances within the cell of the enzyme hence the enzyme is attempting to make the necessary adjustments that can aid in ensuring continuous survival
- What does this suggest to you about organisms that live in highly acidic or highly basic environments?
Organisms living in environments that are highly basic or even acidic have mechanisms of ensuring they are able to maintain the living environment. Very high acidic or even basic environments have the effect of potentially resulting in a destruction of the cells. Some of the organisms living in such surrounding adapt to this environment through the section of a biofilm which acts by slowing down the rate of diffusion of molecules into cells even as others have the potential of changing their cell membrane in a bid to including substances including fatty acids protecting the cells (van Schie et al., 2018).
References
Li, K., Li, M., He, Y., Gu, X., Pang, K., Ma, Y., & Lu, D. (2020). Effects of pH and nitrogen form on Nitzschia closterium growth by linking dynamic with enzyme activity. Chemosphere, 249, 126154
van Schie, M. M., Ebrahimi, K. H., Hagen, W. R., & Hagedoorn, P. L. (2018). Fast and accurate enzyme activity measurements using a chip-based microfluidic calorimeter. Analytical biochemistry, 544, 57-63
