To begin this experiment, four 6-inch pieces of dialysis tubing were cut and soaked in a coffee cup filled with tap water for 2 hours. While waiting, the three following sugar solutions were prepared:…
We then went to see if the sucrose entered the bag unfortunately the benedict's solution showed negative results. The second test ( Bag: 5% ovalbumin Beaker: 1 M sucrose) we put biuret in a test tube with the beaker solution and the indicator showed negative results. Then for the next test (Bag: 1 M Glucose Beaker: distilled H2O) they put Benedict's solution in a test tube with the beaker liquid. The benedicts showed positive results. The next test (Bag 1 M Sucrose Beaker: 1 M NaCl) they put Benedict's solution in a test tube with the beaker liquid. The indicator showed negative results. For the next test(Bag: 1 M NaCl Beaker: distilled H2O) they put silver nitrate in a test tube with the beaker liquid. The silver nitrate showed positive results. The next test (Bag 1 M sucrose Beaker: 5% ovalbumin) they used mass change to determine if the solute could pass through the bag. They weighed the bag before and after. The mass of the bag decreased showing that the H2O passed through the bag. The next test (Bag: 1 M NaCl Beaker: 1 M glucose) they put silver nitrate in a test tube with the eaker liquid. The indicator tested positive. The next test( Bag 1 M Glucose Beaker 1 M sucrose) they put iodine in a test tube with the beaker liquid. The indicator showed positive results. The next and final test (Bag: 1 M glucose Beaker: 5% ovalbumin)…
The water in the test tubes surrounding the dialysis tubings was tested with standard food test reagents at the beginning of the experiment and again after one hour. The results showed that neither starch nor reducing sugar was present in the water surrounding tubes A and B at the beginning of the experiment. (7 marks)…
What does the test of the jar water indicate? That the starch molecules in the dialysis tubing are larger than the in the tubing therefore they cannot be transferred through the process of osmosis or diffusion.…
3. Describe the results of the attempts to diffuse glucose and albumin through the 200 MWCO membrane. How well did the…
In the test for starches, water again will serve a the negative control for the experiment becasue it is inorganic. it appears obvious the 1% starch solution will test positve for starches becasue it is starch. The onion juice should carry starch due to the fact that starch is stored energy for plants and onions are very bulbous, while the sucrose solution again will not test positive because sucrose is only a part of starch.…
The objective for the Spit lab was to test two different types of crackers for the presence or absence of starch and of reducing sugars. Also, to test the chewed cracker, the one that didn’t have a reducing sugar, for the presence or absence of a reducing sugar with the saliva in it. Adding on, another part of the objective is to determine the effect of amylase on starch. For the Chemical Aspects lab, the objectives were to test for the presence or absence of carbohydrates, lipids and proteins in several test samples. In the starch test, the objective was to find the substances that contain starch. In the starch test, iodine was used. In the reducing sugar test, the objective was to find the test materials that have a reducing sugar. In the reducing sugar test benedicts was used. In the grease spot test, the objective was to find all the samples that had a lipid. Another one of the lipid tests were the dye test which was a more specific test to find the substances that all contained a fat by using a solution of Sudan 4 and water. The protein test’s purpose was to determine all the test materials that contained a protein by using biuret solution. The procedure for the Spit lab was to perform the starch test and reducing sugar test on both crackers. Then chew up the cracker that doesn’t have reducing sugars. Next, test the sample for a reducing sugar. The results of the Chemical Aspects lab were that starch, potato juice, cracker solution, and cereal contain starch. In the reducing sugar test glucose, fructose, lactose, and milk contain a reducing sugar. In the grease spot test, salad oil, milk, and chips are lipids. In the dye test, salad oil and chips are fats. Egg albumin, cereal, and cracker mixture show that they are proteins. In the Spit lab the saliva and cracker test showed up positive. The starch test for saltine was positive. The reducing sugar test for saltine was…
Experiment Results Predict Question: Predict Question: Do you think test tube 3 will show a positive Benedict's test? Your answer : a. yes Stop & Think Questions: You included tube 2 to Your answer : d. make sure there is no contaminating glucose in the amylase. Correct answer: b. see what a positive Benedict's test should look like. Which tube is included to detect contaminating amylase in the buffer or in cellulose? Your answer : b. tube 2 Correct answer: d. tube 4 What is the usual substrate for the pancreatic enzyme peptidase? Your answer : a. starch Correct answer: d. peptides Experiment Data: Tube No. 1 2 3 4 5 6 Reagent 1 Amylase Amylase Amylase Cellulose Peptidase Bacteria Reagent 2 Starch Glucose Cellulose Water Starch Cellulose Reagent 3 pH 7.0 pH 7.0 pH 7.0 pH 7.0 pH 7.0 pH 7.0 Time 60 60 60 60 60 60 Temp. 37 37 37 37 37 37 IKI + + + Benedict's ++ ++ ++…
Seal the end if it is not already closed. Next, pick up a pipette and fill it with glucose. (Use this pipette only for glucose) then release the glucose into the dialysis tubing. Place four more pipettes full of glucose into the dialysis tubing. Now it is time to get another pipette (not the one used for glucose) and fill it with starch and release it into the dialysis tubing. Repeat this 4 (four) more times until there is a total of 5 pipettes of glucose and 5 pipettes of starch in the dialysis tubing. Mix the solution. Next, seal the dialysis tubing completely and make sure there is little to no air left in the dialysis tubing. Rise the bag with water. Next, fill a 400ml beaker with 300ml of water. Add 5 pipettes of Lugol´s into the 300ml of water. Mix the solution gently. Place the dialysis tubing bag into the 400ml beaker and leave for 30 minutes. After 30 minutes remove the bag and record your findings. Get 3 test tubes and label them “control” “bag” and “beaker” Next fill an unused pipette with water and pour it into the control test tube. Open the dialysis tubing and fill a pipette of the solution inside using an unused pipette. Repeat again and pour into the bag test tube. Place two pipettes of the beaker solution into the beaker tube. Add one pipettes of Benedict´s into each tube Heat all tubes for three minutes. Record…
The point of this lab is to determine if a substance contains carbohydrates such as a reducing sugar and/or polysaccharides. This will be done by using Benedict’s reagent and Iodine stain tests. Benedict’s reagent will react to reducing substances in the solution by oxidizing it and changing the structure of the reducing sugar to form a colored precipitate. The color of this precipitate can be used to determine the concentration of reducing sugars in the substance. If the precipitate is blue no reducing sugars are in the substance. If the precipitate is bluish green, green, yellow, or orange it does contain reducing sugars. Iodine stain will be used to determine if the solution contains polysaccharides.…
We then repeated this in two more test tubes. We put one of the test tubes in ice (0 C) we put another in the water bath (42 C) then we put one in boiling water (100 C). We repeated the same thing for the boiled amylase. We then checked at five minutes to see if the starch had been digested by the amylase. We did this by putting a little of each of the six samples into a spotting tile. We then added iodine solution to this to see if starch was present or not. I could tell if starch was present or not because if the solution went orange it meant that there was no starch present, so all the starch had been digested, if the solution went blue/black it meant that there was starch present, so the starch had not been fully digested. We recorded the results in a table. We then waited another two minutes so that all together the starch solution had been in there seven minutes. We did exactly the same thing as we did at five minutes we also recorded these results in a…
Abstract dialysis tubing is, made of cellulose because it’s a selectively permeable membrane. In this experiment, we are testing to see if the solution in the beaker moves into the dialysis bag. Which because of that,…
I will change the temperature, at which the solution is heated. I will measure the time it takes for the colour of starch and iodine mixture to disappear. The independent variable in this experiment will be the temperature and the dependent variable time taken between the mixing of amylase and starch solutions and the end of the test. The control variables will…
For unit 7.3 the experiment needed 2 microfuge tubes one labeled "L" for lactose and the other labeled "M" for maltose. The experiment also called for a total of 3 clean plastic pipettes. With one pipette add milk up to the 0.5 line of the lactose tube. With the second clean pipette add maltose solution up to the 0.5 line of the maltose tube. With the third clean pipette, add lactase solution to each tube, until the level of mixture in each tube comes up to the 1.0 line of the tube. Place both tubes in the 40 degrees celsius water bath and incubate them for 10 minutes. The other thing needed is glucose strips. After the tubes have been incubated for 10 minutes, place a glucose strip in each tube for one second. Let it sit for thirty seconds, then compare to the chart provided. For unit 7.4 the experiment called for two microfuge tubes. One labeled "control" and label another one "EDTA". Add 1.25 mL of EDTA to the EDTA tube, add 1.25mL of distilled water to the control tube. Add 3 drops of milk to each tube, invert the tube and let sit for 1 minute. Then add 3 drops of lactase solution to each tube. Then place both tubes in the 40 degrees celsius water bath and leave them for 10 minutes. After the 10 minutes are up, place the glucose strip in each tube and let the strips sit for 30 seconds. Then compare to the charts provided.…
1. (a) (i) The formation of red precipitate indicates the presence of reducing sugar (glucose) in the water ------------------------------------------------------------------- 1 This shows that the dialysis tubing is permeable to glucose / permits the diffusion of glucose into the external solution ------------------------------------------ 1 (ii) (1) Increased amount of precipitates in set-up a indicates the presence of more reducing sugar ------------------------------------------------------------- 1 which comes from the hydrolysis / break down of starch ------------------------------------ 1 catalysed by the amylase / enzyme in digestive juice X -------------------------------------- 1 (2) * saliva / salivary juice -------------------------------------------------------------------------------- 1 * pancreatic juice --------------------------------------------------------------------------------------- 1 (iii) The knot of the dialysis tubing should be tied tightly ------------------------------------------------- 1 The outside of the dialysis tubing should be rinsed with distilled water before immersing into the water. Any ONE of the following : - after putting in the dialysis tubing, the water in the boiling tube should be tested for the presence of reducing sugar immediately. - the digestive juice X should be tested for the presence of reducing sugar. - the dialysis tubing should be examined for any damage. - the volume of distilled water in the boiling tube should be the same. ) ) ) ) ) any ONE------------------------------------- 1 ) ) ) ) Total : 10 marks 1. (a) (i) In the Benedict’s test, the formation of red precipitate indicates the presence of reducing sugar. However, many candidates incorrectly deduced that glucose was present. Some even came to the wrong conclusion that starch could not pass through the dialysis tubing. A considerable number of candidates stated wrongly that glucose passed out of the dialysis tubing by osmosis. These…