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Since the S N 1 reaction involves formation of an unstable carbocation intermediate in the rate-determining step (RDS), anything that can facilitate this process will speed up the reaction. The normal solvents of choice are both polar (to stabilize ionic intermediates in general) and protic solvents (to solvate the leaving group in particular).
The second step is the loss of a sulfur dioxide molecule and its replacement by the chloride, which was attached to the sulphite group. The difference between S N 1 and S N i is actually that the ion pair is not completely dissociated , and therefore no real carbocation is formed, which else would lead to a racemisation.
In the Walden inversion, the backside attack by the nucleophile in an S N 2 reaction gives rise to a product whose configuration is opposite to the reactant. Therefore, during S N 2 reaction, 100% inversion of product takes place. This is known as Walden inversion. It was first observed by chemist Paul Walden in 1896.
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 ...
Serial passage is the process of growing bacteria or a virus in iterations. For instance, a virus may be grown in one environment, and then a portion of that virus population can be removed and put into a new environment.
Gram staining allows for visualization of the bacteria's cell wall composition based on the color the bacteria stains after a series of staining and decolorization steps. [4] This staining process allows for the identification of gram-negative and gram positive bacteria. Gram-negative bacteria will stain a pink color due to the thin layer of ...
The first step involves the Sec and Tat secretory pathways, which are responsible for transporting proteins across the inner membrane into the periplasm. [4] For instance, the Sec pathway is used to transport structural components of the type II secretion system into the periplasm where they can then assemble, while both the Sec and Tat ...
Sigmatropic rearrangements are concisely described by an order term [i,j], which is defined as the migration of a σ-bond adjacent to one or more π systems to a new position (i−1) and (j−1) atoms removed from the original location of the σ-bond. [3]