INTRODUCTION In order to identify what food, and ultimately from which restaurant Parry ate the day of his poisoning, four experiments were carried out. Each experiment tested for the presence of the following four macromolecules in Parry’s vomit: To detect the presence of glucose, Benedict’s reagent was used. The negative control for this reagent remains blue, and the positive control turns green, yellow, or red, in that order from least to greatest concentration; 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; Biuret reagent tested for the presence of protein, which remains light blue with no reaction and changes to purple as a positive control; And brown paper was used to detect any lipids found in the sample. After drying, the towel becomes opaque as a negative control and translucent for the positive control. The results of these tests aided in the determination of the restaurant most likely to have induced the poisoning. PURPOSE The purpose of the lab was to test Parry’s stomach contents using the glucose, starch, protein, and lipid tests; and with the results, determine which restaurant most likely poisoned him. APPARATUS Scoopula Plastic Pipette Glass test tube Spot plate Brown paper towel Benedict’s reagent Water bath Biuret reagent Iodine PROCEDURE Benedict’s Reagent Test (Glucose Test) Using a pipette or scoopula, around five milliliters of the sample are placed
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
1. Benedict’s solution is added to white grape juice and heated. The color changes from blue to orange. Based on this result, what biological molecules are
The purpose of this lab was to test different substances using various procedures to see what biomolecules were present and ultimately find out what restaurant Anna Lyza had eaten at before she died. For the first control test, we used vegetable oil to test for lipids. So, if the solution does not contain lipids, it does not become translucent when placed onto a paper bag square and held up to a light. So, it is a negative result. However, in the presence of lipids, the solution will become translucent when placed onto a paper bag square and held up to a light. Therefore in this case, the result is positive. On the other hand, we used albumin egg to test for proteins in another control test. If the solution does not contain proteins, it will not experience any color change and so it is a negative result. When there are proteins existing in the solution, it will turn bluish/purplish and for this reason it is a positive result. Furthermore in the third control test, we used dextrose to test for simple carbohydrates such as glucose. If the solution does not contain simple carbohydrates, it will not undergo any color change and will remain a blue color. So, it is a negative result in this circumstance. If there are simple carbohydrates present in the solution, the solution will turn reddish and so the result is positive. For the last control test, we used starch solution to test
The iodine test is used to identify glycogen and starch. These polysaccharides combine with iodine to
The primary goal of this laboratory is to correctly identify an unknown substance. To achieve this task, one may use various tests that reveal both chemical and physical properties of a substance. By comparing the results of a known substance and the unknown substance, one may eliminate alternative possibilities and more accurately predict the undisclosed compound. Furthermore, by performing these tests, data can be collected and verified regarding chemical and physical properties of the unknown. Understanding the chemical properties of a known substance aids one’s understanding of the unknown based on comparative analysis of the results of the tests.
A cell, the building block of all living organisms, is composed of four fundamental biomolecules: proteins, carbohydrates, sugars and lipids. Proteins provide a vast amount of functions cells such as they serve as enzymes, provide structural support to cells, and act as antibodies. Reagents are used to spark a chemical reaction. The reagent used to detect protein traces in a substance is Biuret’s. Biuret’s will turn purple if proteins are present and blue if they are none. Biuret’s copper particles, have a charge of +2, are diminished to a charge of +1 when peptide bonds, which are in proteins, are present, creating the color change. Polysaccharides, which are carbohydrates, are most notably known to provide energy to the body, but they also help in breaking down fatty acids. Iodine is the reagent used to determine whether a substance has starch in it. The iodine/starch complex has energy levels that are only for retaining unmistakable light, giving the complex its extraordinarily dark black-blue shade. If there is no starch found, iodine will remain its natural yellowish-brownish color, but if starch is present, iodine will turn blue-black. Monosaccharides, which are sugars, like polysaccharides, provide the body with energy. To detect monosaccharides, the reagent, Benedict’s, is used. Benedict’s reagent is added to a test tube, then it is placed in
*****Safety Note: Please remove the safety goggles and gloves from the lab kit and wear
2. Four unknown samples were included in the lab kit: flax seed meal, potato starch, egg whites, and dried milk. Using the results of the biochemical testing, determine which number corresponds to the correct unknown. (8 points)
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
To perform this test, a tube of broth rich with glucose is acquired. In this tube is phenol red, a pH indicator. Initially, the tube appeared pink in color, indicating a normal pH level. Next, a sample of unknown #44 is introduced into this medium using the aseptic technique, and this is allowed to sit for several days. If the organism is able to ferment glucose, the pH in the medium would decrease and cause the phenol red to exhibit a yellow color. In addition to the straw color, gas can also be produced and trapped inside the Durham tube placed in the medium. This production of acid and gas is a direct result of the fermentation of glucose, as seen with unknown
Pitman Hall is Ryerson’s largest residence located on 160 Mutual St. which is home to nearly 1000 students. The inspection was completed at the residence’s cafeteria where meals were served three times a day on a daily basis. According to DineSafe, this establishment was inspected twice by the Toronto Public Health, where the inspectors evaluate based on the Ontario Food Premises Regulation. The inspection results shows the establishment passed, meaning no infractions were found while inspecting. During inspection, its important food inspectors follow the site-specific risk categorization process to determine the risk levels of the food premises. Risk categorization management (RCM) is a tool that will permit the board of health to deliver a reliable approach to inspection developing and resource distribution, while enhancing public health protection towards food safety. (By notifying the food establishment owner knows
Dr. Morris Greenberg was one of the two investigators and was the Health Department’s chief epidemiologist. He was not convinced that the men suffered from food poisoning, because the symptoms appeared too quickly. He postulated that the men had consumed some type of drug. To prove his claim, he wanted blood samples from the men and wanted the samples to be tested for methemoglobin, a compound formed
Carbohydrates are the product that made up from carbon, hydrogen and oxygen. Carbohydrates are form by the combination of carbon dioxide and water molecules. The carbohydrates contain two specific functional group in it which is the hydroxyl groups and carbonyl groups.A reducing sugar is a type of sugar with is an aldehyde group.This means that sugar can act as a reducing agent.The procces of reducing sugar is isomerisation,example of reducing sugar islactose,maltose,glucose and fructose.All monosaccharides are capable of reducing other chemicals such as copper (II) sulphate to copper oxide.Beside that disaccharides such as maltose and lactose are reducing sugar,however sucrose is non reducing
Name ____________________________ I) Introduction All cells contain four major types of macromolecules: carbohydrates, lipids, nucleic acids, and proteins. In today’s lab, we will be studying three of the four-proteins, carbohydrates and lipids. Various chemical tests can be used to detect the presence of each of these molecules. Most of the tests involve a color change visible to the eye. If a color change is observed, the test is considered positive. If the color change is not observed, the test is negative, indicating that a particular molecule is not present. In all the chemical tests we will be performing, we will also be using a control. In most cases, the control will be a sample of
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.