Step four is basically just where water can now enter and bind to the active site through hydrogen bonding, which is between the hydrogen atoms of water and the Histidine-57 nitrogen. The fifth step is the step where the water and oxygen make a nucleophilic attack on the carbonyl carbon of the acyl-enzyme intermediate. This pushes the carbonyl’s electrons onto the carbonyl carbon, while the Histidine-57 takes one proton from the
In the first step, the leaving group departs, forming a carbocation C+. In the second step, the nucleophilic reagent (Nuc :) attaches to the carbocation and forms a covalent sigma bond. If the substrate has a chiral carbon, this mechanism can result in either inversion of the stereochemistry or retention of configuration. Usually both occur without preference. The result is racemization.
Abstract In this laboratory, methanol is reacted with a tertiary alkyl chloride to make ether. The triphenylmethyl is isolated from the triphenylmethyl chloride. Methanol is then added and the class does the recrystallization . The methanol acts as a solvent for the reaction as a nucleophile. Because it is a tertiary benzylic halide, the reaction is considered an SN1 type.
One purpose of a Wittig reaction is the formation of alkenes from aldehydes or ketones employing a carbo-phosphorous ylide, which is stabilized vie resonance to allow for the carbon bonded to phosphorus to be deprotonate from by a base (Ketcha, 142). The resonating ylide will react with the electrophilic carbonyl carbon of its aromatic aldehyde to produce a betaine intermediate, or a crystalized 4
An EAS reaction pertains to the substitution of an aromatic hydrogen for an electrophile by means of an electrophilic attack on the aromatic ring which in this case is benzene. The product of the reaction was purified by recrystallization and characterized by both NMR spectra and melting point
EC 3 are hydrolases, which forms two products from the substrate via hydrolysis. (Bach, et al. 1961) This is seen in the equation: L- Arginine + H2OL-Ornithine + Urea (Nelson and Cox 2008). The urea cycle is the procedure where ammonia is transformed into to urea. Throughout the urea cycle, the amino acid, arginine, is changes into ornithine- this is another amino acid when hydrated, that is when water was added.
Tertiary alkyl halides tend to give a mixture with both inverted and retained configurations at reaction centers. This is because this reaction proceeds through a stable carbocation intermediate and the carbon at the reaction center goes to sp2 hybridized state (planar geometry). The incoming nucleophile can attack from both sides of the plane and can give two products with retained and inverted configuration. If there is a partial interaction with the leaving group (nucleofuge) with carbocation there will be more product with inverted configuration and if there is no interaction with leaving group racemic mixture can be obtained. The rate of the reaction depends on the formation of a carbocation (which is the slow step) and there is one molecule
This agar comprise of dextrose, lactose and sucrose, which acts as the carbohydrates sources. The medium osmotic balance is maintain by Sodium chloride The fermentation of the carbohydrate lead to acid production of yellow colour agar, detected by the pH indicator in the media, phenol red. Detection of hydrogen sulfide is through the indicator Ferric Ammonium citrate. A black colour will be seen in the medium from the hydrogen sulfide production from thiosuplhate due to FeS production. ,
Water acts as a leaving group in the third step and is removed from the reaction intermediate. In the fourth step, the molecule undergoes deprotonation with the help of the concentrated sulfuric acid to form isopentyl acetate. The reaction that was carried out in the experiment was a reversible reaction. In order to obtain as much isopentyl acetate as possible, Le Chatelier’s principle was used to ensure that we were able to collect a sufficient amount of isopentyl acetate. Le Chatelier’s principle says that if you disturb a system in equilibrium the equilibrium will shift in order to account for the disturbance.
1.3 Organosilane  Monomeric silicon chemicals are known as silanes and any chemical that contains at least one carbon-silicon bond is known as an organosilane. Generally, organosilanes contain three key elements beside silicon; X represents for an organic moiety that is non-hydrolysable which can be either reactive or non-reactive depending on its type. OR\ is a hydrolysable group such as alkoxy or an acetoxy is known to be unstable when present with hydroxyl groups. Finally, R is a space moiety, which can be aryl or alkyl chain. Typically, due to the dual reactivity of organosilane, both alkoxy group (OR\) and non-hydrolysable organic moiety (X), it is used to couple inorganic or organic substrates such as minerals, metals or cellulose and polymeric matrices such as rubber, thermoplastic or thermosets to improve its physical properties.