Counterintuitive physics property found to be widespread in living organisms
Phys.org - Tue 13 Aug 17:01 GMT

Ever since the late 19th century, physicists have known about a counterintuitive property of some electric circuits called negative resistance. Typically, increasing the voltage in a circuit causes the electric current to increase as well. But under some cond…

  However, in a new study published in the New Journal of Physics, Gianmaria Falasco and coauthors from the University of Luxembourg have shown that an analogous property called negative differential response is actually a widespread phenomenon that is found in many biochemical reactions that occur in living organisms.

  As the researchers explained, a negative differential response can occur in biochemical systems that are in contact with multiple biochemical reservoirs.

  As an increase in substrate molecule concentration causes a decrease in the chemical current, this is a negative differential response.

  As a second example, the researchers showed that a negative differential response also occurs in autocatalytic reactions—"self-catalyzing" reactions, or reactions that produce products that catalyze the reaction itself.

  The researchers showed that negative differential responses can arise when two autocatalytic reactions occur simultaneously in the presence of two different chemical concentrations (reservoirs) in an out-of-equilibrium system.

  The researchers also identified negative differential responses in dissipative self-assembly, a process in which energy is needed for a system to self-assemble, making it far from equilibrium.

  In dissipative self-assembly, the negative differential response allows the system to realize a nearly optimal signal-to-noise ratio, ultimately increasing the efficiency of the self-assembly process.