Ph-Amylase Lab Report

Amylase experiment # 2 was done to see how the pH affected the efficacy of the enzyme. First we collected all of the materials that were necessary to make this experiment. We needed five clean test tubes, the following standard solutions, 1% Starch Solution pH 3,1% Starch Solution pH 5,1% Starch Solution pH 7,1% Starch Solution pH 9,1% Starch Solution pH 11

Of the many functions of proteins, catalysis is by far the most vital. When catalysis is not present, most reactions in the biological systems take place very slowly to produce at an adequate pace for metabolising organism. The catalysts that take this role are called enzymes. Enzymes are the most efficient catalysts; they can enhance rate of reaction by up to 1020 over uncatalysed reactions. (Campbell et al, 2012).

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.

specific enzyme (Knowles, 1991). One part of the enzyme, salivary amylase, is that alpha amylase is in the saliva of most animals because this enzyme breaks down starch (Jacobsen, Melvaer, Hensten- Pettersen, 1972). In the presence of starch, this enzyme is present in saliva, but is not present when there is no starch present (Jacobsen, Melvaer, Hensten- Pettersen, 1972). The conditions for salivary amylase to have a reaction with starch would change in temperature and enzyme concentration, as well as, monitoring the pH levels (Jacobsen, Melvaer, Hensten- Pettersen, 1972). Salivary amylase is an enzyme is human saliva that helps in digestion of specific substrates, such as starch (Hudman, Friend, Hartman, Ashton, Catron, 1957). It breaks down starch molecules by splitting maltose from the non-reducing end of a gluten molecule (Jacobsen, Melvaer, Hensten-Pettersen, 1972).

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.

The purpose of this investigation is to discover the effect of pH on the activity of catalase, an enzyme which plays the integral role of converting hydrogen peroxide into water and oxygen, and discover which pH level it will work at the most efficient rate (the optimum). The original hypothesis states that that the optimum would be at a pH is 7, due to the liver, where catalase usually resides, being neutral. The experiment consists of introducing the catalase to hydrogen peroxide, after exposure to certain solutions; hydrogen peroxide, water and hydrochloric acids, all containing the adjusted pH, and measuring the height of froth formed, an observable representation of the activity of the enzyme. The final data indicated that

2. Salivary amylase, an enzyme in saliva that breaks down starch, has an optimal pH of 6.7-7.0. Explain why salivary amylase is active

test the pH of the amylase a drop of the solution should be put on pH

Organisms cannot depend solely on spontaneous reactions for the production of materials because they occur slowly and are not responsive to the organism's needs (Martineau, Dean, et al, Laboratory Manual, 43). In order to speed up the reaction process, cells use enzymes as biological catalysts. Enzymes are able to speed up the reaction through lowering activation energy. Additionally, enzymes facilitate reactions without being consumed (manual,43). Each enzyme acts on a specific molecule or set of molecules referred to as the enzyme's substrate and the results of this reaction are called products (manual 43). As a result, enzymes promote a reaction so that substrates are converted into products on a faster pace (manual 43). Most enzymes are proteins whose structure is determined by its sequence of its amino acids. Enzymes are designed to function the best under physiological conditions of PH and temperature. Any change of these variables that change the conformation of the enzyme will destroy or enhance enzyme activity(manual, 43).

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.

Hypothesis: If we decrease the level of pH in the enzyme Amylase, it will not be able to denature the carbohydrates in the potato starch solution after 10 drops because enzymes are very sensitive to pH levels and lowering it too much will compromise its ability to break them down.

Amylase is a digestive enzyme. The enzyme is found in the salivary glands in your mouth

In this lab our group observed the role of pancreatic amylase in the digestion of starch and the optimum temperature and pH that affects this enzyme. Enzymes are located inside of cells that increase the rate of a chemical reaction (Cooper, 2000). Most enzymes function in a narrow range of pH between 5 through 9 (Won-Park, Zipp, 2000). The temperature for which enzymes can function is limited as well ranging from 0 degrees Celsius (melting point) to 100 degrees Celsius (boiling point)(Won-Park, Zipp, 2000). When the temperature varies in range it can affect the enzyme either by affecting the constant of the reaction rate or by thermal denturization of the particular enzyme (Won-Park, Zipp, 2000). In this lab in particular the enzyme, which was of concern, was pancreatic amylase. This type of amylase comes from and is secreted from the pancreas to digest starch to break it down into a more simple form called maltose. Maltose is a disaccharide composed of two monosaccharides of glucose. The presence of glucose in our experiment can be identified by Benedicts solution, which shows that the reducing of sugars has taken place. If positive the solution will turn into a murky reddish color, where if it is negative it will stay clear in our reaction. We can also test if no reduction of sugars takes place by an iodine test. If starch is present the test will show a dark black color (Ophardt, 2003).

Amylase is an enzyme that is in human’s saliva as well as the pancreas. Enzymes are biological catalysts that speed up a chemical reaction. They break down complex molecules into simple ones. In this case, amylase converts starches (complex molecule) into simple sugars. That is why foods like potatoes for example, may taste sweet to us, because they contain starch. The optimum pH for pancreatic amylase is the pH of 7. In the experiment I have used buffer solutions with the pHs of 2.8, 4 and 6.5. I have also used iodine and starch. Normally, iodine is orange-yellow, however when you add starch to it, the solution will turn blue-black.

In this lab we looked at the role of pancreatic amylase in the digestion of starch and the effect that temperature and pH has on this enzyme. Enzyme’s work as catalysts that increase the rate of chemical reactions within cells (Cooper, 2000). In order to do this, enzymes must show two essential properties: these two fundamental properties of enzymes include increasing the rate of chemical reactions without being eternally altered by the reaction and accelerating the reaction rate with keeping the reactants and products in chemical equilibrium (Cooper, 2000). Enzymatic catalysis is necessary for life. Most biochemical reactions would not occur under the mild temperatures and pressures