Search results
Results from the WOW.Com Content Network
Absolute specificity can be thought of as being exclusive, in which an enzyme acts upon one specific substrate. [8] Absolute specific enzymes will only catalyze one reaction with its specific substrate. For example, lactase is an enzyme specific for the degradation of lactose into two sugar monosaccharides, glucose and galactose.
The 'worst-case' sensitivity or specificity must be calculated in order to avoid reliance on experiments with few results. For example, a particular test may easily show 100% sensitivity if tested against the gold standard four times, but a single additional test against the gold standard that gave a poor result would imply a sensitivity of ...
A comparison of specificity constants can also be used as a measure of the preference of an enzyme for different substrates (i.e., substrate specificity). The higher the specificity constant, the more the enzyme "prefers" that substrate. [1] The following equation, known as the Michaelis–Menten model, is used to describe the kinetics of enzymes:
Each active site is evolved to be optimised to bind a particular substrate and catalyse a particular reaction, resulting in high specificity. This specificity is determined by the arrangement of amino acids within the active site and the structure of the substrates. Sometimes enzymes also need to bind with some cofactors to fulfil their function.
For example, tertiary centres react almost exclusively by the S N 1 mechanism whereas primary centres (except neopentyl centres) react almost exclusively by the S N 2 mechanism. When a nucleophilic substitution results in incomplete inversion, it is because of a competition between the two mechanisms, as often occurs at secondary centres, or ...
There are several types of antibodies and antigens, and each antibody is capable of binding only to a specific antigen. The specificity of the binding is due to specific chemical constitution of each antibody. The antigenic determinant or epitope is recognized by the paratope of the antibody, situated at the variable region of the polypeptide ...
The specificity of a receptor is determined by its spatial geometry and the way it binds to the ligand through non-covalent interactions, such as hydrogen bonding or Van der Waals forces. [ 2 ] If a receptor can be isolated a synthetic drug can be developed either to stimulate the receptor, an agonist or to block it, an antagonist .
Specific energy has the same units as specific strength, which is related to the maximum specific energy of rotation an object can have without flying apart due to centrifugal force. The concept of specific energy is related to but distinct from the notion of molar energy in chemistry , that is energy per mole of a substance, which uses units ...