The Phenyl Red Lactose and Glucose tests are used to determine whether a bacteria is capable of using sugar as a carbon and energy source. The sugar being used is lactose for the lactose test and glucose for the glucose test. The Methyl Red-Voges Proskauer (MR VP) is a mixture of two tests in the same broth, Methyl Red and Voges Prokauer. The with the addition of methyl red indicator, the Methyl Red tests for mixed acid fermenting bacteria. The Voges Prokauer uses Barritt’s A&B (alpha-napthol and potassium hydroxide) as the reagent and tests for bacteria which can ferment 2,3 butanediol.
In the experiment, two beakers were filled with water. One was the control, and consisted of dialysis tubing containing only starch; the other was the experiment and consisted of dialysis tubing containing starch and amylase. Lugol’s reagent was added drop wise into the water surrounding the tubing in both beakers. The beakers were allowed to sit for a short period of time. The solution in the dialysis tubing of the control beaker began to darken into a blue black color as the dialysis tubing is a semi permeable membrane and allows the water and Lugol’s to pass through by diffusion.
There is a space between the peptidoglycan and the secondary cell membrane called the periplasmic space (Betsy, T., & Keogh, J. 2005). Initially Gram staining begins with the basic crystal violet dye and both Gram-positive and Gram-negative appear purple. Then the bacteria are treated with Gram’s iodine, a mordant used in gram staining to intensify a stain (Betsy, T., & Keogh, J. 2005).
Organic Chem. Lab EXPERIMENT 11: ISOLATION OF CAFFEINE FROM TEA LEAVES COMPOUND PROCEDURE Preparation of Tea Solution: We started out experiment by weighing out 5.023g of tealeaves and 2.008g of calcium carbonate powder. These two substances were mixed with 50ml of water and heated under gentle reflux in a round-bottom flask using a condenser apparatus. The hot solution was then filtered and the filtrate was collected and cooled. Extraction and Drying: Using a separatory funnel, the cooled filtrate was extracted with 10ml of methylene chloride.
Analysis of Amino Acids by Paper Chromatography Introduction- Proteins may be thought of natural polymers of amino acids, as the composition of proteins is of amino acids. The technique known as paper chromatography is used to separate amino acids for analysis. In this technique small spots of amino acids are introduced to a piece of porous filter paper. The bottom of the paper is then placed in a small bath of an appropriate solvent. The solvent is allowed to rise up the paper.
The concentration of urea N is determined by the use of Urease. In this experiment Urea was hydrolyzed in the presence of water and urease to produce ammonia and carbon dioxide. This method is based on the pH increase by urea hydrolysis by urease. The pH variation is monitored by a colorimetric quantification of the indicator dye o-cresolphthalein complexone. A blue indophenol compound proportional to the concentration of ammonia was formed when alkaline phenol and sodium hypochlorite reacted with
Chapter # 9 Column Chromatography Purpose The purpose of this lab is to become familiar with the theory and process of column chromatography as it is used to separate two substances, in this case, Lycopene and β-Carotene. This is done by first extracting lycopene from tomato paste and β-Carotene from carrot puree. First, the each paste is treated with acetone to remove as much water as possible. Then, the extraction is performed with three 5-mL portions of dichloromethane. Each organic extract is then dried over anhydrous calcium chloride pellets and evaporated to dryness.
I tested for the presence of glucose by using Chemstrip 9. I tested for the presence of starch by using Lugol’s solution. A positive result for starch is a black-blue or bluish color and a negative result for starch is an amber color. In this experiment water moved into the dialysis bags by osmosis from an area of high concentration (surrounding liquid) into an area of low concentration (dialysis bag). This
In this lab we will investigate how amylase acts on starch, lipase on lipids, and trypsin on protein. Amylase is found in our saliva and breaks down starch for digestion. We will use iodine in the experiment to detect the presence of starch. When iodine makes contact with starch, its natural reddish-brown color turns dark purple. We will detect how long it takes for amylase to react and break down the starch.
Objective: To analyze each solution in order to determine if organic compounds; carbohydrates, proteins, and lipids are present. Hypothesis: If reactions have occurred once each agent has been applied then, this will show weather carbohydrates, proteins or lipids are present. Abstract: My experiment was based on analyzing the following organic compounds: Carbohydrates, proteins and lipids. During my analysis I ran test to gather information containing different color reactions using Benedicts test for reducing sugars, Iodine test for starch, the Biuret test for protein, and the Sudan IV test/Grease Spot test for lipids. After testing the following solutions: onion juice, potato juice, sucrose solution, egg albumen, honey, amino acid solution, distilled water, protein solution, salad oil, known lipid solution, and the unknown solution (3), here’s what I concluded: While some solutions have no reaction to the agent being applied, some color reactions have occurred, hereby leaving me to assume that that carbohydrates, proteins and lipids are present.