Name CHIA ZHEN YONG
Partner’s Name LIEW JUN KEAT, DUNSTAN YOUNG
Class
P1
Date of lab class 10 February 2014
Program
Foundation in science
Unit code
FHSB1214
Unit description
B IOLOGY I
Year and trimester of study
2014 , trimester 1
Title of lab report
Practical 3 : Investigation of Action of Saliva and 3M HCl in Two Carbohydrates Solution
Lecturer’s name
Cik Norkhalidah Binti Jamali
Title : Practical 3 : : Investigation of Action of Saliva and 3M HCl in Two Carbohydrates Solution
Objective : To study the relationship between two carbohydrates solution with saliva and hydrochloric acid.
Result :
Observation
Conclusion
Solution A
Benedict’s test : blue-brick red
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Hydrochloric acid is a very strong acid and it can digest any that contact with it. At high temperature, hydrochloric acid can act as chemical enzyme which can hydrolyses polysaccharide. Hydrochloric acid can break down solution B and starch which are polysaccharide to their respective monosaccharide. Temperatures may have affect the substances such as solutions A and B, saliva, and hydrochloric acid. Saliva is a type of biological enzyme needs an optimum temperature of 37°C to carry out high activity. High temperature causes amylase to become denatured, and the shape of the active site changes, because the bonds in the enzymes are broken because of the heat energy gained to brak the bond. When an enzyme is denatured, it cannot function, hence , no catalyse biological reaction. When solution B is under high temperature, solution B gains heat, which is converted to kinetic energy. Solution B thus have high kinetic energy, and its easier to be catalyzed because the activation energy is achieved easily. Because it has high kinetic energy, the solution can be catalyzed by the hydrochloric acid.
The product that formed after hydrolysed is broken to monosaccharide which are glucose molecules. This is because glucose is a type of reducing sugar that can turns Benedict’s solution from blue to brick-red precipitate. Starch and glucose are consider as carbohydrate . Figure below shows
During the immersion of the magnesium metal in the hydrochloric acid solution, white bubbles could be seen escaping the surface of the metal as gas was produced during the reaction. Depending on the temperature of the hydrochloric acid and the overall molar concentration, the rate of reaction differed but the same signs were shown. During the reaction between the magnesium metal and higher concentrations of hydrochloric acid, it was observed that the test tube grew quite warm to the touch. As the immersed magnesium strip sank down, it appeared coated in a layer of white bubbles that fizzed like a carbonated drink. In the lower concentrations of hydrochloric acid, the strip spent some time floating at the surface of the solution in the test tube, later sinking down to the bottom as the
The chart recorder was started before the concentrations of carbachol were applied to create a baseline. The first concentration of carbachol (10nM) was applied to the rat ileum by adding 50µL of the 0.01mM solution while the chart recorder was run for 30 seconds and then stopped. The Tyrode’s solution around the rat ileum was changed and left for 2 minutes between each concentration that was applied. The second concentration of carbachol (3µM) was applied to the rat ileum by adding 150µL of the 0.01mM solution. all the solutions were applied to the rat ileum using a pipette.
In Part C of the experiment, the process completed in Part B was performed again on the six Kool-Aid drink samples: black cherry, cherry limeade, grape, mixed berry, strawberry, and tropical punch. The cherry limeade, grape, mixed berry, and tropical punch samples were undiluted stock solutions that were used in the SpectroVis. The black cherry solution was diluted with a 2-fold dilution. The 3 mL of black cherry solution was diluted with 3 mL of deionized water. This was done because the Red 40 dye was too concentrated. The strawberry solution was first diluted by a 2-fold but the absorbances values were too high and fell outside the acceptable range of 0-1. Therefore, 8 mL of strawberry solution was diluted with 12 mL of deionized water. These values for all of the solutions were recorded in Table 5. The solutions were emptied down the sink. All the glassware and cuvettes were rinsed with deionized water and dried. The volumetric flasks and caps were returned to the appropriate containers.
Three grams of a mixture containing Benzoic Acid and Naphthalene was obtained and placed in 100 ml beaker and added 30 ml of ethyl acetate for dissolving the mixture. A small amount (1-2 drops) of this mixture was separated into a test tube. This test tube was covered and labelled as “M” (mixture). This was set to the side and used the following week for the second part of lab. The content in the beaker was then transferred into separatory funnel. 10 ml of 1 M NaOH added to the content and placed the stopper in the funnel. In the hood separatory funnel was gently shaken for approximately one minute and vent the air out for five seconds. We repeated the same process in the same manner one more time by adding 10ml of 1M NaOH.
In order to test the predictions of the hypotonic, hypertonic, and isotonic hypothesis for the solution made during the study, four samples of sucrose were taken and placed into two different beakers each containing a different concentration. Beaker 1 is 250- mL and contained 150-mL of 10% sucrose with dialysis tubing A, while beaker 2 (a large bowl) contained 1% sucrose, with dialysis tubing B, C, and D. Tubing A contained 10-mL with 1% sucrose. Tubing B
Lactose is a sugar that can be put into smaller molecules, glucose and galactose. Lactose is when you are not able to digest milk and dairy meaning that the enzyme lactase that breaks down lactose is not functioning properly. ONPG was used as a substitute for lactase because even though it is colorless it helps show enzyme activity by turning yellow. This experiment measured the absorbance ONPG when exposed to lactase within an environment of different salinity’s. The enzyme, lactase, was obtained by crushing a lactaid pill and then was added into four cuvettes. ONPG and salt solution of different concentrations were added and their levels of absorption was measured by a spectrophotometer. The results showed that higher salt concentrations have a lower level of absorption. There were 4 cuvettes and within those cuvettes that solutions within them were being tested and the results showed the more salt solution added with the lactase the lower the absorbance. The less salt solution there was a higher rate of absorbance. The data supported the hypothesis that with increasing NaCl concentration there would be a decrease in enzyme activity.
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.
Upon the addition of water, it was noted that a layer separation occurred and the water layer remained on top, with the 2-methylphenol layer on the bottom layer. Then, conversion calculations were performed to determine the appropriate amount of 3M NaOH to be added to the 2-methylphenol solution. From the calculations, it was determined that 1.08 mL were to be added. 3M NaOH itself was a cloudy solution in appearance and upon the addition of 3M NaOH to the 2-methylphenol solution, it was noted a color change occurred and it became a yellow-green solution. Following this, the same calculations used previously, were used to determine the appropriate amount of sodium chloroacetate, which was found to be 0.38 g (3.26 mmol). Sodium choloroacetate was a white, crushed solid that was then combined with 1 mL of water and was swirled until the sodium chloroacetate completely dissolved. This sodium choloracetate solution was then transferred to the 2-methylphenol solution by the use of a medicine
In this experiment, 0.31 g (2.87 mmol) of 2-methylphenol was suspended in a 10 mL Erlenmeyer flask along with 1 mL of water and a stir bar. The flask was clamped onto a hotplate/stirrer and turned on so that the stir bar would turn freely. Based on the amount of 2-methylphenol, 0.957 mL (0.00287 mmol) NaOH was calculated and collected in a syringe. The NaOH was then added to the 2-methylphenol solution and allowed to mix completely. In another 10 mL Erlenmeyer flask, 0.34 g (2.92 mmol) of sodium chloroacetate was calculated based on the amount of 2-methylphenol and placed into the flask along with 1 mL of water. The sodium chloroacetate solution was mixed until dissolved. The sodium chloroacetate solution was poured into the 2-methylphenol and NaOH solution after it was fully dissolved using a microscale funnel.
A pre-weighed (0.315g) mixture of Carboxylic acid, a phenol, and neutral substance was placed into a reaction tube (tube 1). tert-Butyl methyl ether (2ml) was added to the tube and the solid mixture was dissolved. Next, 1 ml of saturated NaHCO3 solution was added to the tube and the contents were mixed separating the contents into three layers. Once this was completed
Five 250mL Erlenmeyer flasks were obtained. Then, 200mL of hydrochloric acid (HCl) was poured into a 600mL beaker. The gelusil
Add 5mL of gastric juices (contains both pepsin solution and HCl) to test tube 3
My purpose of the experiment is to test what mouthwash will kill the most oral bacteria or prevent the most oral bacteria. What I want to know from this experiment is what kind of mouthwash will prevent the most bacteria and if its wort the money. I choose this topic to see what product will help me maintain the good oral health.
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).