Enzyme Action

Name: Gladys Mae C. Jimenez                                        Date: Feb. 20, 2017

Student no.: 2012-51834                                        

Exercise 6

ENZYME ACTION

1. Introduction

The food that goes into our bodies is first broken down into particles of smaller size in order for the nutrients to be absorbed. The process of breaking down food is digestion. The body system has three certain regions where digestion occurs primarily- in the mouth, the stomach and the small intestine. There are two processes involved in digestion. The first one is the physical digestion where chunks of food are cut or reduced in tiny particles and the second one is the chemical digestion process where enzymes are released in the digestive tract to reduce the size even more into particles that can be absorbed by the epithelium.

There are substances that enhance the biological reactions in the body. Such substances are called enzymes which are proteins that act as catalysts for biological reactions. The function of catalysts is primarily to increase the rate of the reactions but remaining unchanged or without being used up. Like any other catalysts, enzymes do this task as well. The process of catalyzing can be done by lowering the activation energy of a reaction. Almost all biochemical reactions are catalyzed by enzymes. However, since enzymes are proteins, they have a tendency to be denatured in multiple of ways. Enzymes are mostly active under mild conditions. Mostly, they have optimum activity at a neutral pH and at body temperature. Enzymes are also very specific meaning they can only act on one specific substrate or at only one class of related substrate molecules. Their limitations are due to their active sites being very precise. An active site is a portion in the molecule which is complementary in shape to a certain portion in the substrate. An enzyme or catalysts’ in general, have an active site that is complementary to the shape and polarity of the substrate it aims to catalyze. More often than not, only one kind of substrate is compatible to one active site.

1. Materials and Methods

The materials and methods used were as stated in the laboratory manual.

1. Results

1. Starch Digestion

Table 1. Result and observations after Benedict’s test

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Figure 1. Appearance and change of color in the solutions after Benedict’s test

Benedicts’s reagent is used in examining solutions for the presence of glucose. When a Benedict’s reagent is added to a solution, the color will change from blue to green if the solution has low glucose concentrations or red to orange at higher glucose concentrations verifying that the starch was broken down. If the solution remains blue, this means that starch is present and failed to break down. In this part of the experiment, only solution #2 resulted positive in Benedict’s test meaning starch was digested and it has moderate amount of maltose present based on the color yellow mark. Meanwhile, solutions #1, #3 and #4 gave negative result for Benedict’s test. The starch present in the solutions weren’t digested by the enzyme. The increase in temperature and acidity denatured the enzyme resulting to a negative result.

1. Protein Digestion

Table 2. Observation of the egg slices after incubation

        Table 2 shows the results and observations gathered after the solutions with slices of egg were subjected to incubation- the first 3 at 37°C while the last one 0°C. Theoretically, the sliced egg in test tube #2 should change and have a more porous surface compared to the other 3. On our first test #2 that was prepared, we placed excessive HCl and we did observe a porous surface on the slice of egg. However, we did not consider it as a part of our approved result since it didn’t have the same amount of HCl like in the other groups and as stated in the laboratory manual. We failed to detect the change in all the egg slices perhaps due to the low concentration of HCl that was used.

1. Fat Digestion

Table 3. Differences in pH between the solutions in a span of 1 hour

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                Figure 2. Solutions after 1 hour of incubation at 37°C