The unknown bacteria was taken from the NA agar slant and placed on an oxidase strip in a drop of distilled water. Within seconds the bacteria will turn purple if oxidized cytochrome oxidase is present, indicating a positive test. If no color change is observed, no cytochrome oxidase is present and the test is negative. My results for oxidase test were positive. To conduct the oxidase test I first obtained an oxidase strip.
The Loss and then Retrieval of Copper through Multiple Reactions Lab Partners: Justin Dunn and Alexis Almaguer Experiment #2 Section: 506 Intro: All science occurs within rules. One very important rule is that matter can neither be created nor destroyed and this rule will be expressed and proven in this lab by removing copper and then regaining it through multiple reactions, heating, and stirring. This experiment allows the students to learn the different types of reactions as well as learn new techniques within the laboratory such as vacuum filtration and handling hot glassware, but most importantly proves the law of conservation of mass. Materials and Methods: to begin the experiment a 50 ml beaker, hot plate, plastic funnel, aspirator,
Methlyene chloride was a good solvent in this case because its boiling point is 40 degrees C and will boil off before the trimyristin which has a boiling point of 56-57 degrees C. Finally acetone was added to wash the crystals and the solution was vacuum filtered. This process was repeated and the trimyristin was collected. Results: Experimental yield of trimyristin= .64g Experimental melting point of trimyristin= 59 degrees C Percentage yield = experimental-truex100 True Dicussion: The extraction of trimystrin left white crystals resembling a powder. Its melting point was 56 degrees C which was exactly the recorded value. However, given that
Effect of Caffeine on Daphnia Heart rate 24/09/2012 Core Biology Practical (1) Introduction: Caffeine is the drug taken most globally, and can cause health problems such as raised blood pressure. Since we are looking at the heart, we decided to test the effects exposing daphnia to caffeine would have on the daphnia’s heart. Daphnia’s are small water-fleas with transparent body therefore the heart can be visibly seen even without a microscope making the experiment easy to be carried out. Aim: In this investigation, I aim to determine the effect of caffeine on daphnia heart rate Hypothesis: An exposure to higher concentrations of caffeine will cause a distinct increase in the heart rate of daphnia. Null Hypothesis: An exposure to higher concentrations of caffeine will have no effect on the heart rate of daphnia.
(This is usually an inexpensive and easy repair) Here is a link to where I found the best quality and fairly priced swabs. (The Loree Microfiber is especially nice) http://www.forrestsmusic.com/swabs.htm Cleaning Cloths: The best way to keep the oboe keys looking and maintaining themselves great is by using regular cotton cloths or handkerchiefs. NOT silver polishing cloths like most people would imagine. Most silver polishing cloths are a bit too abrasive to be used regularly and will eventually cause damage to the silver plating on the keys. It’s best to use these cloths only 2 or 3 times a year.
Method: Preparation for this experiment required gathering all the needed materials and designing an experiment isolating one variable to determine the effects of temperature on the beet cell membrane. The materials needed for the experiment are: * fresh beets at room temperature * beaker of tap water at room temperature * heating device * fridge and freezer * knife * six test tubes * mm ruler * thermometer * beaker * forceps * Dissecting needle * timer Using a sharp knife, I cut the beet into six (7mm x 7mm x 15 mm) pieces as accurately in measurement
Indigestion and Titration: An Acid - Base Titration Imagine yourself as the Lead Analytical Chemist at Kaplan Industries. Your first big assignment is to investigate the strength of several commercial antacids for the Food and Drug Administration (FDA). They have sent five antacids to be tested with a back - titration that works as follows: • First, each antacid tablet is mixed with 40 mL of 0.1 M HCl — this acidic solution is the same stuff that is in stomach acid, and one antacid pill is nowhere near enough to neutralize all 40 mL of the acid. • So, to see how m uch extra help each antacid pill needs to neutralize 40 mL of 0.1 M HCL, you add 0.05 M NaOH drop - by - drop to back - titrate the solution until the pH is neutral. • What this means is that, the stronger the antacid tablet, the less NaOH it will take to help br ing the acid to neutral.
USES OF PHENOL Phenol cools and numbs skin on contact, kills germs, and reduces the risk for infection in minor skin irritations. It is also caustic, which makes it suitable as an exfoliant. It has been used medically for over 100 years, for these and other applications. In large doses, phenol is highly toxic, but when properly used, it remains a valuable chemical for medical and surgical use. Antiseptic One of the first antiseptics to go into wide use, phenol has been largely replaced by safer chemicals; but it continues to be used for this purpose.
Get 200 mL sample of polluted water and place into 250 beaker 5. Record observations of polluted water into data table 6. Take 100 mL of polluted water to the water testing stations and record data 7. Place a 150 mL beaker under pipe and carefully pour the remaining polluted water into the filter 8. Record the starting time, which is the time all the water was poured in 9.
Since most common ways of killing bacteria is by heat treatment, which can reduce product quality, by eliminating thermal processing, HPP has a minimal effect on the freshness of foods, resulting in better taste, nutrition content, and appearance, thus technology is extremely beneficial for heat sensitive products. High pressure processing can also destroy bacteria that can cause spoilage without a loss of nutrients or quality. In a HPP process, the product is enclosed in a flexible container (usually a small bag or plastic bottle) and loaded into a high pressure vessel filled with a hydraulic fluid (normally water) the pressure is then passed on to the food itself. After the system has reached the desired pressure, products are for a specific time, normally 3 to 5 minutes then the vessel is depressurized, the processed product is then removed