Since late 19 [19459011, physicists have been aware of a counterintuitive property of several electric circuits called negative resistance. Usually, increasing the voltage in a circuit causes the current to increase in power. But under certain conditions, increasing voltage can cause a decrease in current. This usually means pushing harder on electricity bills actually slows them down.
Due to the relationship between current, voltage, and resistance, in these situations resistance produces power instead of consuming it, resulting in a "negative resistance." Today, negative resistance devices have a variety of other applications, such as Gunn's headlights and diodes, which are used in radar guns and automatic door openers, among others. more devices. devices than nature. However, in a new study published in New Journal of Physics Gianmaria Falasco and coauthors from the University of Luxembourg showed that a similar property called negative response is actually a widespread phenomenon found in many biochemical reactions that occur in living organisms. They recognize property in many important biochemical processes, such as enzyme activity, DNA replication, and ATP production. It seems that nature has used this property to optimize these processes and to make things more efficient at molecular scale.
"This counterintuitive, but commonplace phenomenon has been found in a wealth of physical systems after its initial discovery in low-temperature semiconductors," the researchers write in their paper. "We have shown that a negative response to difference is a broad phenomenon in chemistry with major consequences on the effectiveness of biological and artificial processes."
As researchers have explained, a negative response to diversity may occur in biochemical systems related to multiple biochemical reservoirs. Each reservoir attempts to pull the system to a different equilibrium (such as a equilibrium), so that the system is always exposed to competing thermodynamic forces.
If a system is in equilibrium around it, any small siege, or noise, affecting the reservoirs will usually cause an increase in the production rate of some product, in line with positive entropy. The production rate of a product can be thought of as a current chemical. From this perspective, the increase in noise causing the increase in chemical current is similar to the "normal" case in electric circuits where an increase in voltage causes an increase in the electric current.
But when a system that interacts with multiple reservoirs is out of balance, it may respond differently to noise. In an equilibrium system, additional factors are at play, so that increasing noise decreases the chemical current. The negative response to the variation is similar to the case where electric circuits exhibit negative resistance.
In their work, researchers have identified several biological processes that have negative responses to diversity. One example is substrate disruption, which is a process used by enzymes to regulate their ability to quench chemical reactions. When a single substrate molecule binds to an enzyme, the resulting enzyme-substrate complex is decomposed into a product, forming a chemical current. On the other hand, when the substrate concentration is high, two substrate molecules can bind to an enzyme, and this double binding prevents the enzyme from producing more products. As an increase in substrate molecule concentration causes a decrease in the chemical current, it is a negative response difference.
As a second example, researchers have shown that a negative reaction also occurs in autocatalytic reactions – "self-catalyzing" reactions, or reactions that produce products that catalyze the reaction itself. Autocatalytic reactions occur throughout the body, such as DNA replication and ATP production during glycolysis. Researchers have shown that negative responses can arise when two autocatalytic reactions occur simultaneously in the presence of two different chemical concentrations (reservoirs) in an out-of-balance system. , a process where energy is needed for a system to self-assemble, making it far out of balance. Disruption of self-assembly occurs, for example, in the ATP assembly of self-assembly of actin filaments – the long, thin microstructure in the cytoplasm of cells that give the cells their structure.
Nature makes all causes, and the existence of negative differences in response to living organisms is no exception. Researchers have shown that this property provides advantages for biochemical processes mainly in terms of energy efficiency. By blocking the substrate, for example, it allows a system to reach homeostasis with less energy than is needed. In dissipative self-assembly, the negative response to the variation allows the system to realize an almost optimal signal-to-noise ratio, ultimately increasing the efficiency of the self-assembly process.
Researchers get a bad graphene gap by using negative differential resistance
Gianmaria Falasco et al. "Negative response to negative to chemical reactions." New Journal of Physics . DOI: 10.1088 / 1367-2630 / ab28be
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The controversial property of Counterintuitive physics found to be prevalent in living organisms (2019, August 13)
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