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The analysis of these reactions is much simpler if the concentration of substrate A is kept constant and substrate B varied. Under these conditions, the enzyme behaves just like a single-substrate enzyme and a plot of v by [S] gives apparent K M and V max constants for substrate B. If a set of these measurements is performed at different fixed ...
in which e is the concentration of free enzyme (not the total concentration) and x is the concentration of enzyme-substrate complex EA. Conservation of enzyme requires that [28] = where is now the total enzyme concentration. After combining the two expressions some straightforward algebra leads to the following expression for the concentration ...
Enzymes act on small molecules called substrates, which an enzyme converts into products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. The study of how fast an enzyme can transform a substrate into a product is called enzyme kinetics.
The amount of substrate needed to achieve a given rate of reaction is also important. This is given by the Michaelis–Menten constant (K m), which is the substrate concentration required for an enzyme to reach one-half its maximum reaction rate; generally, each enzyme has a characteristic K M for a given substrate.
In biochemistry, denaturation is a process in which proteins or nucleic acids lose folded structure present in their native state due to various factors, including application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), agitation, radiation, or heat. [3]
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:
Substrate presentation; A substrate (purple rectangle) is shown sequestered into a lipid domain (green lipids). The substrate's translocation to the disordered region (grey lipids) presents it to its enzyme (blue oval) where it is hydrolyzed. In molecular biology, substrate presentation is a biological process that activates a protein.
Increasing the substrate concentration increases the rate of reaction (enzyme activity). However, enzyme saturation limits reaction rates. An enzyme is saturated when the active sites of all the molecules are occupied most of the time. At the saturation point, the reaction will not speed up, no matter how much additional substrate is added.