Peroxidase Enzyme Lab Report

Introduction The purpose of this experiment was to determine the presence of the peroxidase enzyme and determine its function in relation to plant cells. This enzyme is significant because peroxidase protects plant cells from invading microorganisms and toxic chemicals. In order to find the presence of this enzyme, this required the group to prepare a sample of a vegetable that would be transferred to a sheet of tissue. After transferring the plant cells to the sheet and adding a series of substances to the cells, a purple staining on the tissue would detect the presence of the peroxidase enzyme.

Procedure The vegetable our group used for this experiment was a carrot. We began by sectioning the carrot into various portions with a knife,

The stain that is found below this region represents peroxidase standard #2, and this has a concentration of 0.1 μg/ml. As we continue down the column, peroxidase standard #3 comes next with a concentration of 1 μg/ml. Finally, the bottom stain is peroxidase standard #4 with a concentration of 10 μg/ml. On another note, the next substance that was added to the membrane sheet is vegetable extract, and this is found in the column to the right of the peroxidase standard. The top stain has 10% vegetable extract while the second stain has 100% vegetable extract. Finally, the printing order of the tissue are as follows: the top left is tissue print #1 (the base), top right is tissue print #2 (bottom half of vegetable body), bottom left is tissue print #3 (top half of vegetable body), and bottom right is tissue print #4 (the

The majority of the data came to show standard #1 having the weakest intensity in its staining while standards #3 and #4 displayed a very dark staining pattern. In addition, on the ranking from highest to lowest in standard staining, the vegetables can be ranked as rhubarb, carrot, celery, asparagus, and parsnip. While comparing the vegetable extracts, the parsnip and asparagus had the darkest stains while rhubarb did not have visible staining for its vegetable extracts. In comparison, the carrot did not have any staining for the 10% vegetable extract. Next, the ranking of vegetable for its proteins from highest to lowest are carrot, asparagus, rhubarb, parsnip, and celery. Again, parsnip and asparagus had the most definition in its staining for the vegetable extract; both samples displayed vivid red and purple colors. On the other hand, rhubarb had very light staining for the extract and it was difficult to see the colors. In our group’s specific staining for the carrot showed that the tip and top half of the vegetable had the darkest staining, signifying there were more proteins present in this region of the carrot. In contrast, the base appeared to have the lightest staining for the distribution of proteins. The types of cells that are stained in this reaction are plant cells that originate in the cell wall; this is because peroxidase plays a role in the synthesis of the plant cell