Austin Peay State University Department of Chemistry
CHEM 1021
BREAKING DOWN STARCH USING SALIVARY AMYLASE Caution: You will be using a Bunsen burner and glassware to create your own constant water bath. Appropriate caution should be exercised when dealing with the Bunsen burner, hot water, and glassware. Purpose: Many plants store their energy in the form of starch, a polysaccharide made from repeating units of the monosaccharide glucose. Our bodies break down starch into the individual glucose units, which are further metabolized into CO2 and water through the process of glycolysis—this is the process we commonly call digestion. The enzyme amylase is present in our saliva and
…show more content…
Pour this into a clean 50‐mL beaker to mix. In a 100‐mL graduated cylinder, put in 1 mL of saliva and 99 mL of water for the 1% solution. Pour this into a clean 150‐mL beaker to mix. 3. Set up 10 reaction tubes (label with a wax pencil) of varying saliva concentrations in a test tube rack as follows: Tube # Saliva Distilled water Final saliva % 1 3 mL 100% 0 mL 100% 2 2 mL 100% 1 mL 66.7% 3 1 mL 100% 2 mL 33.3% 4 3 mL 10% 0 mL 10% 5 2 mL 10% 1 mL 6.7% 6 1 mL 10% 2 mL 3.3% 7 3 mL 1% 0 mL 1% 8 2 mL 1% 1 mL 0.67% 9 1 mL 1% 2 mL 0.33 % 10 0 mL 3 mL 0% 4. Start the reactions: Add 3 mL of a 2% starch solution to the tubes. Mix, and then simultaneously add all 10 tubes to the water bath. After exactly 30 minutes, add 2 drops of the iodine solution to the tubes and record the resultant color. A blue solution means starch still remains, and a colorless solution means all starch has been broken down into glucose.
Revision SP11 Page 2 of 7
Austin Peay State University Department of Chemistry
CHEM 1021
BREAKING DOWN STARCH USING SALIVARY AMYLASE 5. Determine the amylase number: a. Find the most dilute solution of saliva that
4. The stomach maintains a pH of approximately 3 to 5. Do all enzymes function at this pH level? Give an example from one of the exercises.
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
12.Stir then pour 2.5ml of the enzyme mixture into one of the test tubes not allowing any water from the saucepan into the test tube.
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.
Which of the foods that you tested contained amylase? Which did not? What experimental evidence supports your claim?
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.
enzymes that will be used during this lab to test the ability of amylase to break down starch ,a
In part II of the lab six small glass tubes were obtained in a test tube rack. Ten drops of distilled water were then added to test tube 1, five drops to tubes 2-4, and no drops in tubes 5 and 6. Five drops of 0.1M HCl were added to test tube 5 and five drops of 0.1M NaOH to test tube 6. Five drops of enzyme were then added to all tubes except tube 1. Tube 3 was then placed in the ice bucket and tube 4 was placed in the hot bucket at 80-900C for five minutes, the remaining tubes were left in the test tube rack. After the five minutes five drops of 1% starch was added to every tube and left to sit for ten minutes. After ten minutes five drops of DNSA were then added to all the tubes. All the tubes were then taken and placed in the
test the pH of the amylase a drop of the solution should be put on pH
This experiment consisted of setting up a control group of starch in various temperature and then placing both fungal amylases and bacterial amylases in a mixture of starch and placing the solution of amylase and starch in various temperatures of water. After a certain amount of time- different amount of time needs to be used in order to have reliable results- iodine is added in a well on spot plates, then two drops of the mixture of amylase-starch is added from each temperature used, by adding iodine into the plates the mixture will show how much starch was hydrolyzed, this is used to calculate the amount of
To test enzyme activity, an experiment was conducted in the laboratory. In this experiment, the enzyme Amylase was chosen because it assists disassemble the polysaccharide starch. Starch is the main energy storage in plants. Human cells need the energy of stored in the starch to be introduced in the form of Maltose. Maltose is a simple sugar that can be used to generate the energy needed to power cellular work
Human amylase, also more commonly known as saliva, is a digestive enzyme that breaks starches into sugars (McMahon & Skola, 2003). It is what breaks down our food as we are chewing before we digest it, providing us the available energy
Record observations: what color did the solution turn? Orange or blue/ black? This will tell whether the amylase is able to denature the starch solution Orange=Negative Blue/black= Positive
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).
Numerous enzymes are needed in dough to break down starch into simple sugars that yeast can digest. The process is a very complex one, and includes the enzymes alpha amylase and beta amylase. Starch occurs in two different forms, a branched form called amylopectin and an unbranched chain called amylose.