The Effect of P.H on Temperature in Enzymatic Reactions - Lab Report Example

Experiment # The Effect of P.H on Temperature in Enzymatic Reactions Aim of the Experiment This experiment was aimed at ascertaining the relationship that exists between temperature and P.H give that different concentrations of the P.H were used in an enzymatic reaction. In other words, the experiment aimed at establishing the effect of P.H changes on temperatures in reactions that involves enzymes. Safety statement In the experiment, the precautionary measure of not allowing the traces of the hydrogen peroxide spilling on the body. Hydrogen peroxide is a chemical compound that is quite corrosive and is irritative to the skin when it gets into contact with the body. Measuring the volumes of hydrogen peroxide requires great level of accuracy using a pipette. Without care, one can easily sip the hydrogen peroxide and in such situation, a swift remedy should follow. Introduction What are the effects of P.H concentration on temperature regarding reaction that involves the enzymes?. Background information In the enzymatic reactions, both temperature and P.H are factors the affects the rate and efficiency of enzymatic actions on the specific substrates. P.H is the abbreviation of the words, potential of hydrogen ions [H+]. The P.H of a solution is always calculated as the minus logarithm to the base of ten of the hydrogen ions, i.e. – log10 [H+] The formula helps in the calculation of the P.H that ranges from 0-14. In this case all the P.Hs that are below 7 are termed as acidic while those that are above 7 are referred to as basic, the P.H of seven is the neutral one and a good example is water. Ideally, the relationship between temperature and the P.H is much evidenced, assuming the reaction was taking place in a non-enzymatic environment. To ascertain the facts underlying the relationship, it is prudent that the ionization of compounds that contain hydrogen ions in water be considered. The application of the equation developed by Henderson-Hasselbalch will be of help to demystify the relationship between the P.H and the temperature. In the equation, the calculation of the P.H is given by the equation; P.H = pKa + log { [A-]/[HA]} . In the equation, ka is calculated as; ka = [H+][A-] / [HA]. In calculation of the pka then, we use the formulae pKa = - log Ka . The intimate relationship that exists between ka and the Gibbs free energy (G) indicates that ka is a temperature functional. The relationship can be written as G = - RT ln Ka. In a simplified manner the equation can be written as follows pkA = delta G / (2.303 RT). In this case, the Delta G can be substituted by delta H - T * delta S. H and S signifies the enthalpy and the entropy of the reaction respectively (Stein 2011). In substitution of the two we get the equation pKa = (delta H / (2.303 RT)) - (delta S / (2.303 R)) (Stein 299). In the equation arrived at, we can assume the entropy and the enthalpy of the reaction in the equations as factors that can affect temperature changes and use the delta H sign to comprehend the temperature variation. In the event that we use the sign on delta H to determine the temperature changes, there are two possible scenarios; in the endothermic dissociation where the delta is positive, the value of the pka reduces and this eventually increases the temperature. This is a confirmation of the LeChateliers principle that states, in the event that the equilibrium is altered, it will behave in a manner that it absorbs the shock by either shifting to the left or right to continue maintaining the equilibrium (Stein 309). Thus with the decrease in the delta H, the temperature is envisaged to drop. It should not escape our notice that the above scenario is one that takes place in non-biological setting and there is no enzymatic influence experienced. In the event that the enzymes are key players in the reaction, there will be of course significant changes that will be realized and the results will altogether change due to the role played by the enzymes (Stein 311). Temperature is one of the factors that affect the rate of enzymatic reaction in a very significant way; the optimum temperature for enzymatic actions is 37 degrees Celsius but can tolerate the temperature of up to 40 degrees Celsius in the extreme. In the event that the temperature surpasses the critical point, then the enzymes are always deformed such that they lose their structural configuration that helps in key and lock hypothesis during action upon substrates. When the enzymes’ structural configuration is lost we talk of denaturization, in this case they will not be able to act on the substrates hence impairment of their role. With the threat of uncontrolled temperature changes with that of the P.H in the reactants, the biological process that involves the enzymes has a method of arresting the situation through a series of enzyme-instigated reactions. This will always ensure that the P.H of the environment in which the reaction takes place is not abnormally altered to change significantly the temperature level, which subsequently may affect the rate of the enzymatic reactions. Hypothesis There will be no significant change in temperature in an enzymatic reaction upon making changes in the P.H levels of concentrations. In relation to the hypothesis, the P.H level was a subject of alteration to enable temperature observation at different levels to help determine the effect of P.H concentration on temperature. In this situation, P.H was the independent variable while temperature was dependent variable. Data Collecting and Processing The experiment was done in a series of different concentration of hydrogen ions i.e. from the P.H of 4.0 to 8.0 and results recorded as follows. P.H Temperature initial final initial final initial final initial final 4 24 25 24 24.9 24.2 24.6 24.5 25 5 24 26 24.3 26 24.1 25.8 24.3 26 6 24 26 24.5 26 25.5 26 25 25.9 7 24 26 24.1 26 24.1 27 24.5 26.5 8 24 25.2 24 25.1 23 24.7 23.5 25.1 The table below shows the average of the temperature changes of the recorded temperatures in the above table. It shows all the four attempts and the average temperature change of the different P.H concentrations. P.H Temperature changes 1 2 3 4 Average temperature 4 1 0.9 0.4 0.5 0.7 5 2 1.7 1.7 1.8 1.8 6 2 1.5 0.5 0.5 1.125 7 2 3.9 2.9 2 2.7 8 1.2 1.1 1.7 1.6 1.4 Analysis of the Recorded Data Given that the highest temperature was recorded in a neutral P.H, 7.0. it possible to allude that the enzymes worst operated at that particular P.H. It can then be confirmed that based on the temperature trend both in acidic and basic medium, the enzymes were amphoteric in nature and could survive both in acidic and basic media. i.e. operates in a wide range of P.H. The data can also be analyzed statistically by calculating the central tendencies like the mean, mode, median, and even the standard deviation. This is helpful in knowing the degree of spread of the values recorded. It can also be used to establish the precision and accuracy of the data. Mean In this analysis, only the changes in the temperature were considered for the calculation of the central tendencies and the standard deviation. Mean is the average of the values recorded. Mean = ∑X/N =0.7+1.8+1.125+2.7+1.4 5 =1.545 Mode This numerical figure appears most frequently. This according to the changes realized was 2 Median This numerical figure appears in the middle after the digits are arranged in either ascending or descending order 0.4, 0.5, 0.5, 0.9,1, 1.1, 1.125, 1.2, 1.5, 1.6, 1.7, 1.7, 1.7, 1.8, 2, 2, 2, 2, 2.9, 3.9 1.6+1.7 2 =1.65 Since it was an even number, the tenth and the eleventh digits were averaged to find the median. Standard deviation This is the degree of deviation of the figures from the mean Individual figures deviation (Deviation)2 Summation of the deviation 0.7 -0.845 0.7140 0.7140 1.125 -0.42 0.1764 0.8904 1.4 -0.145 0.0210 0.9114 1.8 0.255 0.0506 0.9620 2.7 1.155 1.3340 2.2960 ∑(f-x)2=2.2960 Standard deviation =2.2960/5 =0.4592 Conclusion and evaluation In view of the average temperatures recorded and the P.H concentration against which they were obtained, it is evidenced that the temperature change is affected by the change in P.H concentration. The average temperature is seen to be inconsistent in the sense that they are not assuming any uniform trend of either upside or downward trend. Since in a non-biological environment the temperature change is observed with the increasing level of the potential of hydrogen ions, in the biological system i.e. those that have enzymes, the temperature is regulated and that’s explains the inconsistency in the average temperature recorded above The experiment was also characterized by inherent limitation related to by physiological status of the enzymes. The enzymes as understood operates in a very stringent physiological status that cannot be provided by an experiment in vitro. The enzymes then were not able to do automatic regulation of the variable factors that affects the temperature change. The reagent, sodium peroxide has a corrosive effect that supposedly can be detrimental to bio life, enzymes being one of them is no exemption. This could have contributed to the inconsistency in the recorded results. To mitigate on this, the concentration of the sodium peroxide reagent should be as low as possible to avoid possible impairment of enzymes operations. Work Cited Stein, Ross L. Kinetics of Enzyme Action Essential Principles for Drug Hunters. Hoboken, N.J.: Wiley, 2011. Print. Read More