Digestive System Lab
Introduction
The Digestive system breaks down the ingested food into absorbable forms of nutrients and absorbs nutrients, ions and water from the external environment of the body. It is designed to maximize digestion and absorption. The functional structures of the digestive system are the passage, the glands like salivary glands, gastric glands, pancreatic, intestinal glands and liver. Also, the four layers of the digestive system are mucosa, submucosa, muscularis and serosa. The digestive system is regulated both by the Autonomic system and the Enteric nervous system. The major functions of the Digestive system are; passage and breakdown of food, destruction of ingested bacteria, viruses and toxins, Absorption of nutrients, Elimination of …show more content…
unwanted undigestible substances. In this lab, the enzymes that play a major role in digestion like amylase are going to be studied under the various conditions and a record of each of the conditions are taken to study the effect on the enzymes.
II: Methods As stated before, the purpose of this lab was to study the role that enzymes play in the digestive tract.
In the first part of the lab, we prepared a salivary amylase solution and aggregated acetic acid to detect the presence of mucin. Then, 4 test tubes were made of the following: Tube 1 = 3 ml starch + water + 37 degrees water bath; Tube 2 = 3 ml starch + saliva in water bath; Tube 3 = 3 ml starch (cooled) + 3 ml saliva (cooled) in ice bath; Tube 4 = 3 ml starch + 3 ml saliva 5 drops conc. HCL in water bath. An incubation period of 1 hour was followed and each was tested for starch and maltose. A similar procedure was repeated with pepsin, with the test tubes prepared as follows: Tube 1 = 5 ml pepsin 5% soln + 5 ml HCL (0.5)%; Tube 2 = 5 ml pepsin (5% soln)+ water 5 ml; Tube 3 = 5 ml HCL (0.5%) + 5 ml of water; Tube 4 = 5 ml pepsin 5% soln) + 5 ml NAOH (0.5%). Lastly, the above procedure was repeated with …show more content…
trypsin.
III.
Results:
Tube Starch Maltose Explanation
Water (+) (-) A reddish brown color identifies the presence of starch.
Saliva (-) (+)(+) An orange-yellowish color identifies the presence of maltose
Cooled Saliva (-) (+)(+) An orange-yellowish color identifies the presence of maltose
Saliva, HCl (+) (+) Brown greenish color indicates the presence of both starch and maltose.
Tube Estimated Digestion Explanation
Pepsin,HCl 80 % Based on the pH we notice that 40 % of the substance was digested
Pepsin, water 40% Based on the pH we notice that 80 % of the substance was digested
HCl, water 30 % Based on the pH we notice that 30 % of the substance was digested
Pepsin, NaOH 20 % Based on the pH we notice that 20 % of the substance was digested
Tube Estimated Digestion Explanation
Trypsin,HCl 100 % Based on the pH we notice that 100 % of the substance was digested
Trypsin, water 20% Based on the pH we notice that 20 % of the substance was digested
HCl, water 40 % Based on the pH we notice that 40 % of the substance was digested
Trypsin, NaOH 10 % Based on the pH we notice that 10 % of the substance was digested
Discussion
Amylase is an enzyme found in the saliva, secreted by the parotid salivary gland. It is used to partially digest starch into monosaccharide. From the results, it can be proven that saliva does contain amylase which breaks down starch into a disaccharide called maltose. Since starch break down begins in the mouth, it’s not a surprise to expect the presence of maltose in saliva. However, when HCl is added to the solution, there was no conversion of starch to disaccharide ( maltose) indicating the acid denatured the enzyme and prevented from doing it’s work. This indicates that the enzyme amylase does not work well under an acidic condition. In the second part of the experiment, pepsin which is secreted by the chief cells of the stomach. Pepsin works best in an acidic medium under PH 2. In the results of the experiment
. Thus, it is logical to see this finding in the results. 80% of the substance was digested when HCl was present in the solution, as opposed to water and NaOH. Trypsin works in a similar fashion as pepsin, acting as a proteolytic enzyme. However, they work optimally in basic mediums. Our lab results do not match the theoretical information about the enzyme. As one may see, the substance was completely digested when it was paired with HCl, an acid.
The Digestive system breaks down the ingested food into absorbable forms of nutrients and absorbs nutrients, ions and water from the external environment of the body. It is designed to maximize digestion and absorption. The functional structures of the digestive system are the passage, the glands like salivary glands, gastric glands, pancreatic, intestinal glands and liver. Also, the four layers of the digestive system are mucosa, submucosa, muscularis and serosa. The digestive system is regulated both by the Autonomic system and the Enteric nervous system. The major functions of the Digestive system are; passage and breakdown of food, destruction of ingested bacteria, viruses and toxins, Absorption of nutrients, Elimination of …show more content…
unwanted undigestible substances. In this lab, the enzymes that play a major role in digestion like amylase are going to be studied under the various conditions and a record of each of the conditions are taken to study the effect on the enzymes.
II: Methods As stated before, the purpose of this lab was to study the role that enzymes play in the digestive tract.
In the first part of the lab, we prepared a salivary amylase solution and aggregated acetic acid to detect the presence of mucin. Then, 4 test tubes were made of the following: Tube 1 = 3 ml starch + water + 37 degrees water bath; Tube 2 = 3 ml starch + saliva in water bath; Tube 3 = 3 ml starch (cooled) + 3 ml saliva (cooled) in ice bath; Tube 4 = 3 ml starch + 3 ml saliva 5 drops conc. HCL in water bath. An incubation period of 1 hour was followed and each was tested for starch and maltose. A similar procedure was repeated with pepsin, with the test tubes prepared as follows: Tube 1 = 5 ml pepsin 5% soln + 5 ml HCL (0.5)%; Tube 2 = 5 ml pepsin (5% soln)+ water 5 ml; Tube 3 = 5 ml HCL (0.5%) + 5 ml of water; Tube 4 = 5 ml pepsin 5% soln) + 5 ml NAOH (0.5%). Lastly, the above procedure was repeated with …show more content…
trypsin.
III.
Results:
Tube Starch Maltose Explanation
Water (+) (-) A reddish brown color identifies the presence of starch.
Saliva (-) (+)(+) An orange-yellowish color identifies the presence of maltose
Cooled Saliva (-) (+)(+) An orange-yellowish color identifies the presence of maltose
Saliva, HCl (+) (+) Brown greenish color indicates the presence of both starch and maltose.
Tube Estimated Digestion Explanation
Pepsin,HCl 80 % Based on the pH we notice that 40 % of the substance was digested
Pepsin, water 40% Based on the pH we notice that 80 % of the substance was digested
HCl, water 30 % Based on the pH we notice that 30 % of the substance was digested
Pepsin, NaOH 20 % Based on the pH we notice that 20 % of the substance was digested
Tube Estimated Digestion Explanation
Trypsin,HCl 100 % Based on the pH we notice that 100 % of the substance was digested
Trypsin, water 20% Based on the pH we notice that 20 % of the substance was digested
HCl, water 40 % Based on the pH we notice that 40 % of the substance was digested
Trypsin, NaOH 10 % Based on the pH we notice that 10 % of the substance was digested
Discussion
Amylase is an enzyme found in the saliva, secreted by the parotid salivary gland. It is used to partially digest starch into monosaccharide. From the results, it can be proven that saliva does contain amylase which breaks down starch into a disaccharide called maltose. Since starch break down begins in the mouth, it’s not a surprise to expect the presence of maltose in saliva. However, when HCl is added to the solution, there was no conversion of starch to disaccharide ( maltose) indicating the acid denatured the enzyme and prevented from doing it’s work. This indicates that the enzyme amylase does not work well under an acidic condition. In the second part of the experiment, pepsin which is secreted by the chief cells of the stomach. Pepsin works best in an acidic medium under PH 2. In the results of the experiment
. Thus, it is logical to see this finding in the results. 80% of the substance was digested when HCl was present in the solution, as opposed to water and NaOH. Trypsin works in a similar fashion as pepsin, acting as a proteolytic enzyme. However, they work optimally in basic mediums. Our lab results do not match the theoretical information about the enzyme. As one may see, the substance was completely digested when it was paired with HCl, an acid.