Ccea as Biology Coursework: an Investigation to Measure the Percentage Light Transmission Through a Solution in Which Jelly Cubes Were Immersed over a 24 Hour Period

4. The stomach maintains a pH of approximately 3 to 5. Do all enzymes function at this pH level? Give an example from one of the exercises.

After the serial dilutions of the red and blue dyes were taken, the molarity and absorbance for both dyes were calculated. Using the MiVi = MfVf equation, the concentrations for each value of the red and blue dye were separately calculated. Calculating absorbances calls for setting the correct wavelengths of light for each dye. In this case, the 470 nm wavelength for red dye and the 635 nm wavelength for blue dye was needed to find the maximum absorbances. The absorbance was found by blanking the colorimeter and entering the concentrations. After both values of the absorbances and concentrations were found, the values were then graphed in order to obtain the equation of the relationship between absorbance and concentration.

The Beers Law calibration experiment used many concentrations of crystal violet solutions. Each of these solutions were test and analyzed in order to determine the absorbance of each concentration The results were than graphed and produced a slope of 1.00E05 with an intercept of -2.21E-02.

MicroLAB Kinetics program was opened, then the colorimeter was calibrated to a 100% transmission by filling a marked, clean, clear cuvette, about ¾ full of deionized water. The cuvette was wiped with a Kimwipe from the outside before putting it in the colorimeter. The cuvette was inserted in the chamber, then the cap was closed, and the Read Blank button was clicked to start the calibration.

Although the experiment was as fair as it could have been, there were some factors that were beyond our control. Firstly, the tubers that we used may not have been from the same specimen,

The graph below shows the effect of temperature on relative rate of action of enzyme X on a protein.

Beer’s Law is a direct liner relationship between the absorbance of light are a selected wavelength and the concentration the absorbing species in the solution. (Sullivan 241). Beer’s Law shows a relationship between several concentrations. To determine if the determine our data consistent with Beer’s law, we will plot a graph of absorbance versus concentration with a linear regression

The measurements that it reads are the absorbance and the transmittance. Absorbance is the amount of light that is absorbed by the solution, while transmittance is the amount of light that passes through the solution. The solute that was used in the experiment was Copper (II) Sulfate, which has a pale blue color. Since the Copper (II) Sulfate is blue in color, it will absorb light in the orange range of the light spectrum, and so 600nm is the adequate wavelength to measure the transmittance. A direct relationship between the amount of light absorbed by the solute and the concentration of the sample substance was established by the Beer-Lambert Law.

When measuring the jelly powder or when moving the jelly powder in to the cups, it is possible that there could have been either less than 42 grams or more than 42 grams therefore giving too much or too little of the amount required. When using the graduated cylinder it is possible that some of the water maybe have been lost during the moving process. Measurements of the fresh and canned pineapples may not have been completely the same. Also, there was no thermometer so there is a possibility that the temperature of the cold and hot water may have been different between the fresh and canned pineapple jelly, having different temperatures could have been a factor to the setting process. Therefore, the experimental errors faced were based on inaccurate measurements, and could have affected the results of the

For example, when dissolving the samples, too much liquid could have been added, affecting how saturated the solution was, and ultimately affecting the accuracy of the results. To prevent such an error, one could gradually add water and patiently mix the solution to make a saturated solution. Additionally, errors could have come from not making a solution as close to 1.0 M of the compound. In order to prevent this possible error, one could have calculated the volume of the water (in mL) needed to make the 1.0 M solution, which would result in having more precise results. Lastly, being that there are multiple calculations involved, being careful and observant in correctly recording the values could prevent simple

Throughout the experiment, Allura Red was continually mixed with distilled water to form many different concentration solutions. The colorimeter was then used to determine the absorbance of each solution. Red light is around 650 nanometers on the visible light spectrum, but the colorimeter was set at 470 nanometers. This was done because Allura Red has the greatest absorbance when exposed to a light that is blue in color, which is why 470 nanometers was used.

The average absorption for 50°C needed to increase, as other outside sources acquire, since there is a relationship between the increase of temperature and the average amount of absorption of blue light. This was most likely due to manipulative errors achieved while doing the experiment. Regardless of that result, calculations for the correlation between the two variables, demonstrated that there is a positive correlation, as shown on Table 3. A 95% confidence statistical analysis also verified that the results were not due to chance, and the standard deviation demonstrated accurate results. 95% was used to demonstrate that there is a relationship between the two and that it is not specifically due t chance.

Background Problem: 1.Equation: a.Absorbance = proportionality constant * path length (cm) * concentration (mol/L) i.Proportionality constant represents how each substance individually absorbs light. Path length takes into account how thick or thin the measuring tool is of the substance. Concentration represents

It is often the case that an enzyme is almost entirely effective only under a specific pH range. Once beyond the range, the enzyme’s behavior exhibits almost no productive activity. The pH where the enzyme is most effective is referred to as the optimal pH. Most enzymes within human functions and cells have optimal pHs around a neutral pH, though certain enzymes exhibit prime functionability under extremely acidic or basic pHs.

To investigate whether light intensity of incoherent lights varies inversely with the square of the distance holds true in real-life situations and under laboratory conditions. Techniques utilised in the experiment included measuring the distance from the light source to the light sensor, recording the light intensity of a light source and recording observations with accuracy. The light from the light source that passes through the cardboard cylinder tube changes as the distance from the light sensor increases. The results show that light intensity of incoherent lights varies inversely with the square of the distance in real-life situations and under laboratory conditions.