Science

Abstract

In lectures leading up to the experiment, it was stated clearly that variations in pH, temperature and substrate concentrations has profound effects on enzymes. This practical not only re-enforced these ideas, but explores the chemistry behind it. The idea of an enzyme denaturing after it has reached its optimum pH or temperature was clearly indicated by the first and second part of the experiment. The second part of the experiment also brought out the idea of the relationship between temperature and enzyme activity, which has been discussed as been inversely proportional to a certain point. Another useful concept drought into play is Michaelis-Menten's saturation curve, which states that as enzyme concentration increases so does the substrate concentration, which creates a saturated solution. The basis of this report will explore the concepts mention above.

Introduction

It is the common understanding to those in the science field that the activity of an enzyme is strongly effected by the pH, temperature and the changes in concentration of a substrate. Reflecting back on lectures it is safe to say that changes in pH alter the ionization of the charged amino acid, whereas changes in the temperature creates an unstable protein from increased kinetic energy, which in both cases results in the formation of a denatured species. The aim of this experiment was to reinforce the theory and to analyze the effects of pH, temperature and the effect of increasing the substrate concentration of an enzyme. Having said that, one needs to reflect back to the effect of substrate concentration of enzymes and put to use Michaelis-Menten's curve, which states by experimental calculations that keeping the amount of enzymes constant would gradually increase the substrate concentration of the given reaction.

The idea of increasing the pH was demonstrated in the first part of the experiment. Pre-incubating the test tubes starts the optimization period, this part of the experiment was not a test for temperature but to grasp the idea of how changes to pH effect enzyme activity and which of the given was the optimum pH for the alkaline phosphotase, this information derived from calculations and reading the optimum pH of a graph. In much the same manner, the idea of increasing the temperature over time was demonstrated in the second half of the experiment. The idea, like that of the first was to find the optimum working temperature for alkaline phosphatase before it denatures.

Looking at the effect of substrate concentrations of enzymes, the idea of using Michaelis-Menten's curve would be to draw on three major points when interpreting the graph. As scientists one needs to be able to understand and identify if the enzyme require a small amount of substrate to become saturated indicated by a small Km value, large amounts of substrate concentrations indicated by maximum velocity and lastly enzymes of natural substrates, indicated by the lowest Km value. Not only will this report address all the above but will work towards discussing results obtained and utilizing the lecture material to grasp the concept of variations to pH, temperature and effects of substrate concentration.

Materials - ' As per Brau el (2006)

Results

Looking at the graph for the effects of pH on enzymes activity, it would be safe to suggest or say that the apparent optimum pH for alkaline phosphatase is approximately 11.5. This result is indicated by the peak on the graph. It is also useful to note that Beer -Lamberts equation was used to calculate the number of moles of enzyme activity. In much the same manner, one would interoperates from the graph that the optimum working temperature for alkaline phosphotase is approximately 37C. If we take a closer look at the effects of substrate concentration on enzyme activity, the graph suggests that the Vmax is equal to 22.5nm and Km is equal to 11.2nm.

Tables



Table 1) - Effect of pH on enzyme activity



Table 2)- Effect of Temperature on enzyme activity



Table 3) - Effect of substrate concentration [S] on enzymes

Figures - 'refer to graphs'

Discussion

Looking closely at the results obtained for effects of pH and temperature on enzyme activity. It would be safe to suggested that after a certain point the changes in both pH and temperature totally inhibit the enzyme from catalyzing. It is important to understand that the activity of an enzyme is shown to decrease on either side of the pH optimum simple because substrate require a large amount of energy to reach the transition state, clearly indicated by incubating test tubes at 37C. At this state chemistry would have us understand that molecules are excited and jump from one energy level to another. The enzyme then stabilizes at the transition state, reducing the energy required to form its species and hence, reducing the energy required to form its products. This as a result changed the shape of the enzyme so that the substrate can no longer fit the lock and key model. As most scientists would suggest, the enzyme had reached a point of denaturing. Reflecting back on the effects of pH on enzyme activity, it would be safe to say that a deprotonated environment was created as the solution were to basic. This in theory effects the polar group of the enzyme. Looking back on the results obtained and drawing particular interests

...