Design Investigation on Amylase, Lab Report Example

Design

Aspect 1

The experiment aims to answer the following question: What nutritional needs determine the amount of the enzyme amylase available when it is needed to catalyse the hydrolysis of starch into sugars?

Understanding how the cell uses amylase to break down starch is important because the cell stores a majority of its energy in the form of starch. When food is needed, it must initiate a process to break down the starch into a usable form, which is sugar. Therefore, it is important to determine the process that activates amylase because this process must be regulated to ensure that the cell does not starve or does not overproduce sugar when it is not needed. To do so, plant cells will be examined at various stages of starvation. The null hypothesis is that the amount of amylase produced will be the same for all plants at all levels of starvation. The alternative hypothesis is that the amount of amylase produce will be different for all plants at all levels of starvation, with the plants with the highest levels of starvation producing the most amylase.

In this experiment, the independent variable will be the level of starvation the plants receive. To starve the plant, they will be given no water and no light. Moderately starved plants will be given just light or just water. The dependant variable will be the amount of amylase produced, which will be measured by the rate of reaction of the conversion of starch to sugar. The control will be the plant that is exposed to no light and given a normal amount of water. The same amount of light or darkness and amount of water or lack of water will be applied to each of the plants that will be used in this experiment.

Method

Aspect 2

• Four peace lily plants (a common household plant with green leaves) will be obtained
• Prior to the experiment, they will all be placed in an area with adequate sunlight and be given water until it appears that the soil is moist; they will be left in this condition for at least three days prior to the experiment to ensure health
• One plant will be labelled “Control”, one will be labelled “No Water No Light”, one will be labelled “No Light”, and the remaining one will be labelled “No Water”
• The plants labelled “No Light” will be kept in a dark closet, plants that are allowed light will be left in a brightly lit windowsill, and plants that will be allowed water will be given half of a cup of water; all four plants will be left in their labelled condition for 24 hours
• After 24 hours have passed, clippings will be taken from the middle of each plant until the clippings from each plant weigh 1 gram
• The leaves will then be mashed until liquid is seen to ooze out of them
• Amylase quantity will be measured for each sample using BioVision’s Amylase Activity Colorimetric Assay Kit, which works by assigning amylase a colour and then measuring it with spectrophotometer
• A second collection of plant extract will be generated from each of the samples
• A starch solution will then be made by mixing 20 g of potato in 50 mL of cold water; this mixture will then be added to about 900 mL of boiling water
• Once the solution is clearly mixed, the total solution will be made to measure 1 L; to ensure starch is present, an iodine indicator will be used
• The liquid mixture obtained from the leaves will be applied to .5 mL of the starch solution; a separate test will be done for each of the four plants mentioned above
• After mixing the plant extract well with the starch solution, the absorbance of each reaction will be measured using a spectrophotometer at 620 nm
• These values will be recorded and compared to amylase activity
• The pH of the starch solution will be kept constant; it will be measured by a pH meter and either HCl or NaOH will be added to maintain these levels throughout the experiment

Aspect 3

This method allows me to collect enough data because it examines the concentration of amylase needed to convert starch to sugars in two ways. First, it determines the amount of amylase available in plants based on their nutritional access. Next, it determines the activity of the amylase based on its ability to interact with starch. There is enough data here for a statistical test. It would be useful to perform a student’s t-test that compares the control data in both portions of the experiment to the plant labelled “No Light No Water”. In addition, the activity could be plotted on a graph that could help predict the amylase levels at varying concentrations outside of those used in this experiment. After the first four data plots are obtained, it may be useful to repeat the experiment using varying levels of light and water to ensure that different levels of amylase are obtained. About three trials should be done to ensure precision and accuracy of the data collection. Averages and standard deviation would then be calculated.