1.Find THE AMOUNT OF REDUCING SUGARS AND STARCH IN YELLOE AND GREEN BANANAS by Using the Benedict's test nad Iodine test. Why the Benedict's solution should be used in excess.

4. There are other types of reagents used to determine what type of biomolecule a substance is. For example, copper ions present in Benedict’s reagent reacts with the free end of any reducing sugars, such as glucose, when heated. Originally blue in color, these copper ions are reduced by the sugar, and produce an orange-red colored precipitate. Alternatively, iodine-potassium iodide (IKI) may also be used when working with starch. IKI contains special tri-iodine ions which interact with the coiled structure of a starch

The results for Benedict’s test for reducing sugars before hydrolysis, the control dH2O had no color change, as well as sucrose and raffinose. Gelatin became a dark blue and egg albumin a light greyish blue. Glucose yielded a dark orange, milk albumin turned orange, and starch had a yellow precipitate. In the Benedict’s test for reducing sugars by hot acid hydrolysis, the control dH2O was blue or no reaction. Glucose turned a brownish-orange; sucrose, a reddish-brown, raffinose, light pink; starch, a dark yellowish-orange; gelatin, violet; milk powder, a light yellow; and egg albumin, a greyish-violet. In the Lugol’s test for polysaccharides, the control dH2O turned yellow or no reaction, as well as glucose, sucrose, raffinose, milk powder and albumin. Starch was clear with blue-violet on the bottom (precipitate) and gelatin turned a slightly opaque white. In the test for polysaccharides remaining after hydrolysis with Lugol’s solution the control dH2O was yellow or no reaction. Glucose, sucrose, raffinose, starch and gelatin also had no reaction. Milk powder had a white precipitate and particle suspension. Egg albumin had an even greater white precipitate and particle suspension. In Biuret’s test for proteins there was no reaction for dH2O, glucose, sucrose, raffinose, and starch. Gelatin, milk powder and egg albumin all turned slightly violet with bubbles.

The iodine test is used to identify glycogen and starch. These polysaccharides combine with iodine to

The purpose of this experiment was to find out the nutrient content of unidentified food samples and to use chemical reagents to see if the unidentified foods for sugar, starch, protein and fat (lipid) content. After comparing the color changes in each unknown substance then you will be able to see the amount of sugar, starch, protein or fat there is in the unknown substance.

b) Benedict test the solution color will change from blue to pink/orange red, indicating simple sugars are present. Lugols test the solution color will change from yellowish brown to dark purple, indicating starch and polysaccharides are present. Sudan iV test the lipid content will turn into red, indicating lipids are

The students first prepared to construct a standard curve. To do this, each group measured the absorbance of starch solutions of unknown concentrations treated with IKI (General Biology I, Martineau, Dean, Gilliland, & Soderstrom, Lab Manual, 2017, 45). The absorbance values were determined for a range of samples, and plotted on a graph. A line of best fit was then used as a reference to determine the amount of starch present in unknown samples.

The Benedict test, is a test to determine whether a solution has reducing or non-reducing sugars. If the Benedict's test is negative, that means there is not reducing sugars. Next, the Lugol's test is to determine if there is starch in a substance. If the solution is yellow or orange after a Lugol's test, that means it is negative. If the results of a Lugol's test is purple or black, then it is

Overall the mass of the potato slice for the groups went down during the experiment. The ranges of weight change warried from around 0.2 to 0.3 grams

We then recorded the initial color. We placed each tube in boiling water for one minute and recorded the color results and gave our conclusion. To test for starch using Lugol’s solution, we reused the test tubes and added a squirt of the solution. We recorded the final color and then our conclusion for each content. To test for lipids using paper towels, we placed a drop of solution and we let it stand for one minute. We then recorded our observation, if it was dry or not dry and wrote our conclusion for each sample. To test for proteins using Biuret’s reagent, we added a squirt of stock solution plus a few drops of Biuret’s solution. We wrote the initial color. We then shook the solution and waited for two minutes before recording the results. After the two minutes, we wrote the final color and conclusion for each content. For the unknowns, we wrote the odor and appearance of each content and then tested the benedict’s, starch, lipid, and protein test and wrote our conclusion.

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

For this experiment, we have to prepare our phosphorylase which extracted from a potato. We prepared by weighed about 250 grams of peeled potato and cut it into cubes. The extracts then blended with 100mL of 0.1M NaF. After filtered the contents into a clean 250mL centrifuge bottle, we centrifuged it for 3 minutes. Then, separated the supernatant into a centrifuge bottle, which is our phosphorylase preparation. The enzyme assay used in this experiment today is the iodine test. As the iodine reacts with starch, it will form a brown, blue or black precipitate due to the iodine ions forcing into a linear arrangement. The endpoint of the enzyme reaction indicates the presence of starch by using the iodine test to determine. The faster the endpoint is reached, the less active the phosphorylase is.

Solutions and color reaction for Benedict’s test for reducing sugars and 2 iodine test for starch

3 drops of Lugol’s solution is added to each tube. Presence of starch is indicated by dark purple color occurrences. The amount of starch is indicated by the shades of reddish brown.

During the Benedict's test, the contents of tube B did not change, indicating the absence of sugar in that particular substance. However, the contents of tube A did change orange indicating the presence of sugar in that substance. During the Lugol's test, the content of tube A did not change dark purple indicating the absence of starch in that substance However, the content of tube B changed to dark purple

Iodine was used to test for the presence of starch, remaining yellow for its negative control and becoming a blue-black colour if a reaction occurred;