Ankita Batra
Section 13156
The Effect of pH Level on Starch Digestion by the Activity of Amylase and the Examination of the Rate of Starch Disappearance Using Iodine Solution
Introduction
A key enzyme found in the saliva of humans, alpha-amylase, is involved in the early stages of starch digestion. This type of amylase is classified by its glycosidic bonds and is mainly found in the bodies of animals. The digestion of starch will begin with the enzyme in saliva and will continue to break down starch as the food bolus reaches the duodenum (Butterworth et al., 2011). Therefore, alpha amylase is a significant component in the digestion process and also plays a major role in energy storage.
Starch is the main source of carbohydrate in the human diet, so it is essential to have an enzyme that assists in the efficient hydrolysis of starch into sugars. Amylase catalyzes this reaction by breaking the glycosidic bonds present, which results in maltose, a disaccharide, glucose, and varying lengths of oligosaccharides with alpha-limit dextrins and alpha-configurations (Marini, I. 2006). Although the amylase enzyme is abundant from the secretion of the pancreas and salivary glands, it can also be obtained from different sources such as other mammals, plants, and microorganisms.
Since there are many sources for obtaining amylase, the enzyme also has many applications in industrial processes. Amylase acquired from bacteria and fungi can be beneficial in the chemical and pharmaceutical
There are many types of enzymes and each has a specific job. Enzymes are particular types of proteins that help to speed up some reactions, such as reactants going to products. One of them is the amylase enzyme. Amylases are found in saliva, and pancreatic secretions of the small intestine. The function of amylase is to break down big molecules of starch into small molecules like glucose; this process is called hydrolysis. Enzymes are very specific; for example, amylase is the only enzyme that will break down starch. It is similar to the theory of the lock
The control group was expected to see a decrease in absorbance because of the starch being digested by amylase. Our experimental group contained everything the control group did, including the Carb Cutter pill. If the Carb Cutter proved to actually work it would show a steady high absorbance, proving that it constantly keeps amylase from digesting the starch.
How pH Affects the Break Down of Starch by the Enzyme Amylase Hypothesis: The optimum pH for the reaction of starch with amylase is pH 7. PH values lower or higher than this value will result in a slower rate of reaction. Amylase works in the range pH 3 to pH 11.
1) Amylase is utilized to break down starch molecules into more simple sugars for use by the body. It performs this function by hydrolyzing glycosidic linkages in the polysaccharide chain.
Specifically, alpha-amylase is produced by the salivary glands of Homo sapiens (Humans) as well as many other mammalian species and is encoded by the gene AMY1A (Tracey 2017, p.22). The enzyme alpha-amylase is able to uptake polysaccharides including starch and glycogen as a substrate then hydrolyze the alpha-1,4-glycosidic linkages that connect the monosaccharides together (Tracey 2017, p.37). This is the reason as to why salivary amylase is also referred to as alpha-amylase (Tracey 2017, p.22).
In this lab experiment the action of the enzyme Amylase was observed on starch (the substrate). Amylase changed the starch into a simpler form, the sugar maltose, which is soluble in water. Maltose then breaks down the glucose chains of starch in the pancreas and intestines. Amylase is present in human saliva, and begins to act on the starch in the food while still in the mouth. Exposure to heat or extreme PH (acid or base) will denature proteins. Enzymes, including amylase, are proteins; if denatured enzymes can no longer act as a catalyst for the reaction. In the presence of potassium iodide, starch turns a dark purple color; however maltose does not react with I2KI. The rate of fading of starch allows a quantitative measurement of reaction rate.
Hydrolysis of starch for fungal amylase Aspergillus Oryzae and bacterial amylase Bacillus Licheniformis at different temperatures.
1. Explain why you can’t fully test the lipase activity in tube 5. _Measurement of lipase activity uses a decrease in pH. Because the pH in Tube #5 is already very low, it is hard to tell if fatty acids are released.__
During these experimental procedures, the implication of multiple different temperatures on fungal and bacterial amylase was studied. In order to conduct this experiment, there were four different temperatures used. The four temperatures used were the following: 0 degrees Celsius, 25 degrees Celsius, 55 degrees Celsius, and 80 degrees Celsius - Each temperature for one fungal and one bacterial amylase. Drops of iodine were then placed in order to measure the effectiveness of the enzyme. This method is produced as the starch test. The enzyme was tested over the course of ten minutes to determine if starch hydrolysis stemmed. An effective enzyme would indicate a color variation between blue/black to a more yellowish color towards the end of the time intervals, whereas a not so effective enzyme would produce little to no change in color variation. According to the experiment, both the fungal amylase and bacterial amylase exhibited a optimal temperature. This was discovered by observing during which temperature and time period produced a yellow-like color the quickest. Amylase shared a similar optimal temperature of 55 degrees Celsius. Most of the amylases underwent changes at different points, but some enzymes displayed no effectiveness at all. Both amylases displayed this inactivity at 0 degrees Celsius. At 80 Celsius both the enzymes became denatured due to the high temperatures. In culmination, both fungal and bacterial amylase presented a array of change during it’s
Bacterial amylases operate at higher temperatures than do fungal amylases. Fungal amylases react rapidly at lower temperatures; fungal amylases are used as an agent for alcohol fermentation for grain (Underkofler et al, 1958). Fungal amylases is said to be denatured – change shape (Alberte et al, 2012), at high temperatures above 60° C and bacterial amylases on the other hand are stable and show little denaturing at temperatures up to 85°C 3 The question answered by the experiment is if the temperature is not within the range of the enzymes (fungal and bacterial amylase) optimal temperature (higher temperature) then will the enzymes denature and if the enzymes are placed in lower temperature from optimal the activity then will it slow down enough to stop all reaction, meaning each enzyme will not be operating efficiently. Knowing about a bacterial amylases and fungal amylases optimal temperatures are important for knowing which food products and industrial products it can be used on to conserve the product because then the producer knows about which products it can be incorporated into depending on the temperature it is manufactured at.
What Happens to Starch Molecules in My Mouth Priyanka Balla Goal: I want to make sure that my evidence and my reasoning make sense and support my claim. When starch molecules are in our mouth, enzymes in our saliva start a chemical reaction which makes starch molecules break down and turn into glucose. There was evidence of starch being broken down into glucose when we did lesson 4 in our book, we tested to see if five different solutions contained glucose and starch. During the experiment, we tested to see if 10 drops of cracker solution and 10 drops of cracker solution and amylase contain glucose. During the experiment there was a color change in the solution that had the cracker solution and the amylase.
The effects of temperature on fungal amylase Aspergillus oryzae, and bacterial amylase, Bacillus licheniformis ability to break down starch into maltose was studied. The study determined the optimal temperature the Aspergillus oryzae and Bacillus licheniformis was able to break down the fastest. The starch catalysis was monitored by an Iodine test, a substance that turns blue-black in the presence of starch. Amylase catabolizes starch polymers into smaller subunits. Most organisms use the saccharide as a food source and to store energy (Lab Manual, 51). The test tubes were labeled with a different temperature (0°C, 25°C, 55°C, 85°C). Each test tube was placed in its respective water baths for five minutes. After the equilibration process, starch was placed in the first row of the first row of the spot plate. Iodine was then added to the row revealing a blue black color. The starch was then added to the amylase. After every two minute section a pipette was used to transfer the starch-amylase solution to place three drops of the solution into the spot plate row under the corresponding temperature. Iodine drops was placed in the row. Color changes were noted and recorded. The results showed Aspergillus oryzae was found to have an optimal temperature between 25°C and 55°C and Bacillus licheniformis was found to have an
Amylase is an enzyme that is located in human saliva. It is solely accountable for breaking down starch as a way to start the breakdown of food and is one of the first steps of digestion. The time at which the enzyme starts the chemical reaction with starch is called the reaction rate. In order to study how amylase works against starch, this experiment consisted of two tests; each testing a different condition of amylase. The first test was to simply study the reaction between saliva and amylase and note the reaction rates. The second test was to see if increasing the pH would decrease the reaction rate or halt it all together. Saliva was collected, diluted, and tested for reactions between starch and amylase. Another sample of saliva was collected, diluted, and had its pH increased and tested for reaction rate. The findings after the experiment was conducted aligned with the original hypothesis. The change in pH did show a significant decrease in the reaction rate.
The objective of this lab was to assess the effect that temperature and pH had on pancreatic amylase. Amylase is an enzyme involved in digestion and is secreted by both the pancreas and salivary glands (Pandol, 2010). Both salivary and pancreatic amylase display the same enzymatic activities through their role in the digestion of starch (Pandol, 2010). The goal of both salivary and pancreatic amylase is to hydrolyze starch thus breaking down the polysaccharide into a disaccharide such as maltose (Pandol, 2010). As a result, amylase breaks down these sugars making them more easily absorbed in the body during digestion (Pancreatic Cancer Action Network, 2015). Through this lab we learned about the role of pancreatic amylase and how this enzyme operates under certain conditions.
The dough must contain some alpha amylase to be able to digest the portion of starch that is amylopectin. If the alpha amylase is too much in the dough the starch will completely liquify. Alpha amylase attacks starch virtually wherever along its chains, producing smaller chains of different lengths. These chains can hold smaller units called dextrin’s that contain numerous units of glucose. Beta amylase can then digest these dextrin’s into maltose.