Ethyl vinyl ether was used to protect –OH on glycidol based on a literature reported protocal.59 In a typical procedure, 0.675 mol glycidol and 200 mL ethyl vinyl ether were loaded in a round-bottom flask, to which 1.25 g TsOH was then added. The reaction was allowed to proceed at room temperature (RT) for 3h. The resulting mixture was then purified by washing with 100 ml saturated aqueous solution of NaHCO3 for 3 times. The organic layer obtained was dried by MgSO4. After filtration of MgSO4, the excess ethyl vinyl ether was removed by rotary evaporation.…
Sterols in plants are almost completely derived from acetyl-coenzyme A (acetyl-CoA). Acetyl-CoA is dimerized to acetoacetyl-CoA that then forms 3- hydroxy-3-methylglutaryl-CoA (HMG-CoA) by a condensation reaction. HMG-CoA is reduced to mevalonic acid by 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), a rate-limiting step in human isoprenoid biosynthesis. HMGR over-expression in transgenic tobacco plants resulted in increased levels of total sterols, indicating that HMGR is a limiting enzyme also in plant sterol biosynthesis (Schaller et al., 1995). The next step in sterol synthesis is to form squalene from mevalonic acid, and this is performend by a series of reactions where the final step is catalysed by the squalene synthase enzyme (SQS).…
Results In the lab, 478 trials were conducted using a total of 956 crickets. The 478 pairs resulted in 264 wins for the resident cricket and 214 wins for the intruding crickets. These results produced a chi squared value of 5.230. The p-value calculated from this lab was .022.…
However, this would make a carboxylate and regenerate the alcohol because of the acid-base reaction. Another option would be to make the carboxylic acid a better electrophile by adding a NaCl halide but this is too expensive and difficult to be done in a teaching lab setting. Instead, the Fischer approach is used in which the reaction is performed under acidic conditions. The acid first protonates the oxygen in the carboxylic acid making it positively charged. This makes the carbonyl carbon more electrophilic by making it less electronegative because the electrons are being drawn towards the positively charged oxygen atom.…
1. a. My data demonstrated the law of conservation of mass in part 5 of the experiment, dissolving sugar in water. The law of conservation mass states that matter cannot be created or destroyed by can enter or leave the system. The system’s change in mass was 0.00 grams, resulting in support of this statement.…
Lab 4 in Chem 115 has three parts all calculating density. In part one, a 100 mL beaker, a volumetric pipet, and an analytical scale were obtained. To begin, the mass of the beaker was taken using an analytical scale. Then, 10.0 mL of an unknown liquid was transfered to the beaker using the volumetric pipet. Next, the mass of the beaker and liqiud was recorded along with the letter identifying the unknown liquid.…
INTRODUCTION The purpose of this experiment was to demonstrate the stereochemistry of the electrophilic addition using (E)-Stilbene, a trans-isomer of ethylene. Bromine was added and reacted with (E)-Stilbene to form an alkene. A product was made with both a meso-stilbene dibromide and a d/l-stilbene dibromide, which is trans-stilbene dibromide. DISCUSSION AND CONCLUSION For the reaction to form these two different compounds with the same starting reactants, the double bond of (E)-Stilbene has to attack one bromide.…
A. Heating Magnesium: This station consisted of magnesium, a slim, flexible, silver metal and a Bunsen burner. We used crucible tongs to hold the magnesium over the Bunsen burner until it began to ignite. When it first ignited, sparks were seen and the flame emitted a bright, white light. The flame spread across the magnesium and eventually turned it into a white, ashy substance.…
The purpose of this lab was to determine if a change in mass occurs during a chemical reaction in a closed system. To conduct this experiment, the mass of the test tube, rubber cover, and other materials must be measured. To prevent the test tube from rolling off of the balance, a plastic cup was used to hold it in place, but the group had to remember to zero out the cup on the balance so the cup’s mass will not affect the masses of the objects the group was trying to measure. During this investigation, it was determined that there is a 0% change in mass after a chemical change in a closed system, because the mass of the copper and sulfur before heating did not change after being heated. Although the substances had changed in appearance and could no longer be considered…
The focus of this lab was to identify an unknown organism based on its characteristics and the results from each of the tests. There will be various of test to choose from in order to identify the unknown organism, which will eliminate numerous possibilities and narrow it down to one. All the fundamental skills that we have learned and practiced in the lab will be used to perform on our unknown such as aseptic technique, microscopic examination, the use of differential media, and determining if it’s positive or negative. Performing aseptic techniques is the most crucial step that requires the utilizing of transferring, inoculating, and storing bacterial cultures and media. Aseptic technique is defined as procedures that prevent contamination…
Chemical changes are everywhere from everyday things such as baking to scientific things such as changing one gas into another. Physical changes are changes that can be observed with senses and change a certain property or properties to a substance but it still remains chemically the same. This can include changes in the state of matter, size and shape. Chemical changes are when the substance is changed chemically with its properties changing with it. The substance with change from one substance to another.…
Rafaela Hajdini Bio 104- 55 November 11th 2014 Fermentation Lab Report Abstract: Introduction: Cellular respiration is a reaction that the majority of living organisms partake in to get adenosine triphosphate (ATP), by obtaining chemical energy, to synthesize in three different phases; glycolysis, citric acid cycle, and the electron transport chain. Both glycolysis and the citric acid cycle are anaerobic pathways which means that oxygen is not need to form energy.…
Paracetamol is one of the world’s most beneficial and resourceful analgesic and is widely used in present day. An analgesic, can be defined, as a chemical compound that relieves pain, reduces fever and inflammation. It works by hindering the enzyme cyclooxygenase which acts a catalyst to convert fatty acids to prostaglandins. Prostaglandins cause pain and inflammation to peripheral and central points in the nervous system2. Paracetamol, or Acetaminophen is created by the synthesis and preparation of an amide.…
Lactate dehydrogenase (LDH) is an oxidoreductase found in both eukaryotes and prokaryotes. LDH catalyses the formation of lactate and NAD+ from pyruvate and NADH, during the last step of anaerobic glycolysis. The reaction is also catalysed in the other direction by LDH during the Cori cycle. This reaction can be assayed using spectrophotometric techniques; peak absorbance of NADH is at 340nm, but the peak absorbance of NAD+ is 259nm (Powers, et al., 2007). Enzyme assays are performed to measure the rate of an enzyme-catalysed reaction, known as the enzyme activity.…
Purpose: To test the effect of inorganic and organic catalyst concentration and surface area on the reaction rate. Introduction: In this experiment the experimenters will seek to determine what factors determine the rate of a reaction with a catalyst. A catalyst is a molecule that starts a chemical reaction, but it is not part of the reaction it is causing.…