Search results
Results from the WOW.Com Content Network
where is the ratio of the rate of the substituted reaction compared to the reference reaction, ρ* is the sensitivity factor for the reaction to polar effects, σ* is the polar substituent constant that describes the field and inductive effects of the substituent, δ is the sensitivity factor for the reaction to steric effects, and E s is ...
The PTB domains facilitate interaction with the activated tyrosine-phosphorylated insulin receptor. The PTB domain is situated towards the N terminus . Two arginines in this domain are responsible for hydrogen bonding phosphotyrosine residues on an Ac -LYASSNPApY- NH2 peptide in the juxtamembrane region of the insulin receptor.
RNA folding problem: Is it possible to accurately predict the secondary, tertiary and quaternary structure of a polyribonucleic acid sequence based on its sequence and environment? Protein design : Is it possible to design highly active enzymes de novo for any desired reaction?
The determining factor when both S N 2 and S N 1 reaction mechanisms are viable is the strength of the Nucleophile. Nuclephilicity and basicity are linked and the more nucleophilic a molecule becomes the greater said nucleophile's basicity. This increase in basicity causes problems for S N 2 reaction mechanisms when the solvent of choice is protic.
These plots were first introduced in a 1970 paper by R. A. More O’Ferrall to discuss mechanisms of β-eliminations [2] and later adopted by W. P. Jencks in an attempt to clarify the finer details involved in the general acid-base catalysis of reversible addition reactions to carbon electrophiles such as the hydration of carbonyls.
In organic chemistry, steric effects are nearly universal and affect the rates and activation energies of most chemical reactions to varying degrees. In biochemistry, steric effects are often exploited in naturally occurring molecules such as enzymes , where the catalytic site may be buried within a large protein structure.
It is a common misunderstanding [2] that the energy not delivered by the battery due to Peukert's law is "lost" (as heat for example). In fact, once the load is removed, the battery voltage will recover, [3] and more energy can again be drawn out of the battery.
Therefore, the reactive catalytic species should decrease in concentration, leading to an overall slower reaction rate. If the correction factor is less than one, the reaction displays an asymmetric depletion, also known as a negative non-linear effect. In this scenario, the heterochiral catalyst is relatively more reactive than the homochiral ...