PH Levels Affecting Enzyme Activity

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

The practical was carried out to investigate the effect of pH on the reaction of the enzyme acid phosphatase.

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.

Figure 2 is a representation of the average saturation of each cuvette at a specific point time as a function. The y-axis shows the specific saturation points from figure 1, and the x-axis provides the different levels of pH. The pH scale provided on the x-axis ranges from 0 to 14, 0 being the most acidic and 14 being the most basic. The point chosen from figure 1 was the saturation levels of each cuvette at 110 seconds. The saturation point was chosen because in the previous graph at time 110 seconds the reactions of

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

I forecast that the more concentrated the hydrogen peroxide is the higher the volume of

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

Enzymes are high molecular weight molecules and are proteins in nature. Enzymes work as catalysts in biochemical reactions in living organisms. Enzyme Catecholase is found on in plants, animals as well as fungi and is responsible for the darkening of different fruits. In most cases enzymatic activities are influenced by a number of factors, among them is temperature, PH, enzyme concentration as well as substrate concentration (Silverthorn, 2004). In this experiment enzyme catecholase was used to investigate the effects of PH and enzyme concentration on it rate of reaction. A pH buffer was used to control the PH, potato juice was used as the substrate and water was used as a solvent.

In the following experiments we will measure precise amounts of potato extract as well as Phenylthiourea, combined with or without deionized water and in some instances change the temperature and observe and record the reaction. We will also investigate the different levels of prepared pH on varying samples of the potato extract and the Phenylthiourea and record the results. We will answer question such as what is the best temperature for optimum temperature reaction as well as the best pH level for the same reaction.

Wear safety goggles to protect the eyes from any splashes and wearing gloves is recommended when handling acids and

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.

How does decreasing the levels of pH by adding Hydrochloric acid affect the Amylase’s ability to break down potato starch solution?

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).

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