Lecturer Date Introduction Theoretical Background Procedure The procedure was segmented into two categories, the reaction set up and the crude product isolation. Reaction set up The magnetic stirrer was prepared through placing it in the fume cupboard. 1 mmol of L-Phenylalanine was placed and weighed in a 5 mL conical vial. After that, a spin vane was inserted into the vial while adding 0.75 mL of 1M H2SO4 solution. During the addition of the sulphuric acid, the solution was stirred at room temperature until the amino acid (L-Phe) completely dissolved. An ice bath was prepared and used for cooling the L-Phenylalanine solution at a temperature of 40C (a selected temperature lower than 50C). Once the solution was cooled, the first portion …show more content…
“Diazotization of L-phenylalanine results in the unstable aliphatic diazonium salt 2, which is believed to undergo a rapid, intramolecular SN2 reaction to give the highly strained R-lactone (3) (3)”. “In a second, slower, intermolecular SN2 reaction, 3 reacts with the solvent (water) to open the lactone and yield the final product, (S)-2-hydroxy-3-phenylpropanoic acid (4)”. “Because this process occurs with two SN2 reactions, the final product has a net retention of configuration”. “This reaction has the added advantage of being environmentally friendly: the reaction is run in aqueous solution, using a safe amino acid and generates no hazardous waste requiring disposal”. “This experiment illustrates some important chemical concepts, including: Water solubility dependence on the state of ionization of a compound, Stereospecificity of the SN2 reaction, Measurement of optical activity, Effect of diastereotopic protons in the 1 H NMR spectrum”. “The starting amino acid is highly soluble in the acidic solution of the reaction, the amphoteric nature of L-phenylalanine is apparent at the start of the reaction”. “The L-phenylalanine solution is cooled and then the aqueous NaNO2 solution is added with stirring”. “The reaction mixture begins to form tiny bubbles as the diazonium salt forms and nitrogen gas is liberated by the intramolecular reaction with the carboxylic acid”. “Reaction occurring as the Nitrogen bubbles form”. “This rapid intramolecular reaction reinforces the concepts
Experiment VIII was performed to analyze SN2 and SN1 using tertiary and primary substrates and use gas chromatography (GC) to examine the SN1 reaction. The product of the SN2 reaction was classified as n-butyl iodide by using infrared spectroscopy and gas chromatography mass spectroscopy and the product of the SN1 reaction was identified as of t-butyl chloride by using infrared spectroscopy and gas chromatography. For the SN2 reaction, 7.62 grams of n-butyl bromide, 20.0 grams of sodium iodide, and 79.1 grams of acetone were used to produce 3.12 grams of n-butyl iodide. The limited reagent was identified as n-butyl bromide and the theoretical yield of n-butyl iodide was calculated as 10.3 grams. The percent yield of this reaction was calculated
When the electricity is turned on, the proteins and Tris-glycine enter the stacking gel. In stacking gel with pH 6.8, the N-terminal amino group of the proteins and amino acids are protonated at equilibrium, which makes them less negative. The average electrophoretic mobility is very slow. A Gly-chloride ion boundary is formed since glycine moves slower than chloride ion. However, glycine still runs slightly faster than other proteins.
Experiment # 3 – Resolution Of ( )- -Phenylethylamine Name: Krishna Binu Class: Chem 2020 Due Date: October 23, 2015 Table 1 Shows the experimental results. Name Result Mass of Amine (g) 3.32 Mass of Salt (g) 1.26 Observed Rotation of Isolated Amine (Degrees) -36.33 1) Draw the chemical structures of the two diastereomeric salts produced in Part A using a proper perspective (line-angle) representation.
Explain the relationship between the ionisation of amino acids and pH |Structural diagram of the neutral structure| |Structural diagram of positively charged structure| |Structural diagram of negatively charged structure| Explain how the form of an amino acid, whether positively charged, negatively charged or neutral, depends of the pH of the solution ? If you increase the pH of a solution of an amino acid by adding hydroxide ions, if this is done then the hydrogen ions will then be removed from the -NH3+group . . To test if it is now a negative ion a process called electrophoresis.although it is colourless its position can be detected using ninhydrin. If the amino acid has dried and then heated gently it would appear as
The purpose of this experiment was to learn about the electrophilic aromatic substitution reactions that take place on benzene, and how the presence of substituents in the ring affect the orientation of the incoming electrophile. Using acetanilide, as the starting material, glacial acetic acid, sulfuric acid, and nitric acid were mixed and stirred to produce p-nitroacetanilide. In a 125 mL Erlenmeyer flask, 3.305 g of acetanilide were allowed to mix with 5.0 mL of glacial acetic acid. This mixture was warmed in a hot plate with constantly stirring at a lukewarm temperature so as to avoid excess heating. If this happens, the mixture boils and it would be necessary to start the experiment all over again.
Benzyne Formation and the Diels-Alder Reaction Preparation of 1,2,3,4 Tetraphenylnaphthalene Aubree Edwards Purpose: 1,2,3,4-tetraphenylnaphthalene is prepared by first producing benzyne via the unstable diazonium salt. Then tetraphenylcyclopentadienone and benzyne undergo a diels-alder reaction to create 1,2,3,4-tetraphenylnaphthalene. Reactions: Procedure: The reaction mixture was created. Tetraphenylcyclopentadienone (0.1197g, 0.3113 mmol) a black solid powder, anthranilic acid ( 0.0482g, 0.3516 mmol) a yellowish sand, and 1,2-dimethoxyethane (1.2 ml) was added to a 5-ml conical vial.
By completing this experiment, knowledge collected about optimal pH in enzymes will help
purpose the propose of this experiment was too see if the chemical reaction of a enzyme can be made faster. Hypothesis I think that a warm environment would be best to make an enzyme’s reaction faster. because a protein can move faster in heat.
The first test that gave us an indication that catharant hus ovalis (species Z), is most closely related to Catharanthus roseus (Rosy periwinkle) is test 5 (Test for enzyme M). We found that both species Z and rosy periwinkle have enzyme m present which suggests that share similar enzymes, which helps prove that species Z can produce the same alkaloids. Enzymes are used to increase reaction and help with digestion/ synthesis. Enzyme m, which is present in periwinkle, is used to synthesize the alkaloids of interest. We tested the 3 other species to see if this enzyme was present to help bring us to our conclusion of which is most similar to rosy periwinkle.
LABORATORY REPORT Activity: Enzyme Activity Name: Natalie Banc Instructor: Elizabeth Kraske Date: 09.22.2016 Predictions 1. Sucrase will have the greatest activity at pH 6 2. Sucrase will have the greatest activity at 50 °C (122 °F) 3. Sucrase activity increases with increasing sucrose concentration Materials and Methods Effect of pH on Enzyme Activity 1. Dependent Variable amount of product (glucose and fructose) produced 2.
Experiment 2 Report Scaffold (Substitution Reactions, Purification, and Identification) Purpose/Introduction 1. A Sn2 reaction was conducted; this involved benzyl bromide, sodium hydroxide, an unknown compound and ethanol through reflux technique, mel-temp recordings, recrystallization, and analysis of TLC plates. 2. There was one unknown compound in the reaction that was later discovered after a series of techniques described above.
Arianna Diazwightman - Biology Lab Report PID - 5869132 Gabby Vazquez, Catalina Ortega, and Jerry Lab Section 41 Table 5 Lemme Break It Down Ft. Amylase The effects of temperature on the ability of an enzyme to break down starch. Abstract
Hardee and his group developed a process of activation of aliphatic carboxylic acids taking 3, 3-dichlorocyclopropenes in presence of tertiary amine base , DIPEA (diisopropylethylamine)[22] FIGURE 3.3 ACTIVATION OF ALIPHATIC ACID Racemization is frequent in the course of coupling reaction at the C-terminal amino acid residue due to the ionization of the α-hydrogen atom and formation of an oxazolone intermediate in peptide synthesis, so of course this will not reagent of choice in peptide synthesis, where suitable peptide coupling reagent can be selected, which is out of scope of this review.[22] 3.2 SELECTED PROCESS Out of all the processes mentioned in the survey, these processes were selected on the behalf of having most appropriate reaction conditions and environment of the research lab, i.e modification with
Bio Chem lab Report 04 Enzyme Biochemistry Group Member: Chan Man Jeun Duncan (16002621) Law Sze Man (16000478) Introduction Enzyme is a protein base structure substance in our body. It works at a biocatalyst that will catalyzing the chemical reaction, which helps to speed up the chemical reaction. Enzyme could only function in specific shape, and the shape of enzyme is depending on the environment, therefore it is hard for an enzyme to function well in an extreme environment. The aim of this experiment is to see can the enzyme functions normally in different environment(pH, temperature and salt concentration) via using starch solution, amylase from saliva, 0.5M HCl solution, 0.5M NaOH solution and NaCl solution, and using iodine solution