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The negative feedback loop used to successfully inhibit the inhibitor, p27, is another essential process used by cells to ensure mono-directional movement and no backtrack through the cell cycle. When DNA damage occurs, or when the cell detects any defects which necessitate it to delay or halt the cell cycle in G1, arrest occurs through several ...
In natural selection, negative selection [1] or purifying selection is the selective removal of alleles that are deleterious. This can result in stabilising selection through the purging of deleterious genetic polymorphisms that arise through random mutations.
From the point of view of control theory, the voltage clamp experiment can be described in terms of the application of a high-gain output feedback control law [13] to the neuronal membrane. [14] Mathematically, the membrane voltage can be modeled by a conductance-based model with an input given by the applied current I a p p ( t ...
Allelic exclusion is a process by which only one allele of a gene is expressed while the other allele is silenced. [1] This phenomenon is most notable for playing a role in the development of B lymphocytes, where allelic exclusion allows for each mature B lymphocyte to express only one type of immunoglobulin.
Attenuation is a second mechanism of negative feedback in the trp operon. While the TrpR repressor decreases transcription by a factor of 70, attenuation can further decrease it by a factor of 10, thus allowing accumulated repression of about 700-fold. Attenuation is made possible by the fact that in prokaryotes (which have no nucleus), the ...
Cells utilize product inhibition to regulate of metabolism as a form of negative feedback controlling metabolic pathways. [2] Product inhibition is also an important topic in biotechnology, as overcoming this effect can increase the yield of a product, such as an antibiotic. [3] Product inhibition can be competitive, non-competitive or ...
In the process of depolarization, the negative internal charge of the cell temporarily becomes more positive (less negative). This shift from a negative to a more positive membrane potential occurs during several processes, including an action potential. During an action potential, the depolarization is so large that the potential difference ...
Perceptual control theory (PCT) is a model of behavior based on the properties of negative feedback control loops. A control loop maintains a sensed variable at or near a reference value by means of the effects of its outputs upon that variable, as mediated by physical properties of the environment.