By Christopher Cronkite: Abstract Operons are regions of prokaryotic DNA that contain multiple genes without an interfering termination sequence. Because of this, the genes in an operon are all transcribed into a single mRNA. In this way, a cell can regulate transcription of multiple, related genes using the same mechanisms. In Escherichia coli, the lac operon codes for three proteins involved in lactose catabolism. Expression of this operon is regulated by both a repressor and enhancer that function dependent […]
Written by Jacob Barlow Purpose: The purpose of this experiment is to synthesize a Grignard reagent (Grignard Reaction) from 2-bromopropane which is then used to synthesize 2-methyl-1-(4-methylphenyl)propan-1-ol from p-tolualdehyde and the created Gringard reagent. The product was then purified using liquid-liquid extraction and rotary evaporation. It was then identified using infrared and nuclear magnetic resonance spectroscopy. Chemical Equation: This is the chemical equation for the creation of the Grignard reagent. This is the chemical equation of the reaction of the […]
Written by Allison Guindon The rate constant of the reduction of methylene blue was determined by spectroscopy. The experimental koverall was determined to be 9.4±4.2L2/mol2/s at 295.15K. The experimental value was compared to the known value of 5.0L2/mol2/s resulting in a percent error of 88%. Sources of error include, not mixing the solutions and placing them into the spectrometer fast enough, or fingerprints on the cuvette. BACKGROUND: Reaction rate constants (k) measure the speed of chemical reactions. Reaction rates depend […]
Written by Aarti Prabhu Objective: To purify and concentrate a fermentation mixture by both simple and fractional distillation Procedure Observations 1.) Add 5 g of Celite to the fermentation mixture, mix thoroughly, and then vacuum filter into a large filter flask. Material had settled in the r.b. Flask, but dissolved again when mixed with the Celite. The mixture had a brownish white tint. After filtering, the solution looked yellow and smelt like alcohol. 2.) Transfer the filtered solution back to […]
Written by Aarti Prabhu Objective: To be able to conduct a reflux reaction, and practice improving recrystallization and mp determination, by the bromination of trans-cinnamic acid to form 2,3-dibromo-3-phenylpropanoic acid, and connect syn and anti addition concepts and stereochemical consequences (erythro & threo) from the addition mechanism. PROCEDURE: Procedure: Observations: Combine 100 mg of trans cinnamic acid in a 4 mL conical vial. 0.1025 g of trans cinnamic acid was added. Add 0.7 mL of dichloromethane and 350 uL of […]
Written by Denise Tram In this lab, we are to analyze the different processes that will be used in laboratory to help us gain experience in identifying different anions and how we can become familiar with different anions by observations of the reactions and products. In this lab we separated precipitates and by doing this we were able to confirm the reactions that create a precipitate and we used this to identify which anions can be reacted in which […]
