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A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place. In a chain reaction, positive feedback leads to a self-amplifying chain of events. Chain reactions are one way that systems which are not in thermodynamic equilibrium can release energy or increase entropy in order to ...
It is a self-sustaining sequence in which the resulting products continue to propagate further reactions. [1] Examples of chain reactions in living organisms are lipid peroxidation in cell membranes [2] and propagation of excitation of neurons in epilepsy. [3]
A chain of events is a number of actions and their effects that are contiguous and linked together that results in a particular outcome. In the physical sciences , chain reactions are a primary example.
Chain initiation is the initial generation of a chain carrier, which is an intermediate such as a radical or an ion which can continue the reaction by chain propagation. Initiation steps are classified according to the way that energy is provided: thermal initiation, high energy initiation, and chemical initiation, etc. Thermal initiation uses ...
For example, the most widely studied bacterium, E. coli strain K-12, is able to produce about 2,338 metabolic enzymes. [1] These enzymes collectively form a complex web of reactions comprising pathways by which substrates (including nutients and intermediates) are converted to products (other intermediates and end-products).
The termination step can vary, in both its actual chemical reaction and when it will occur. [6] Lipid peroxidation is a self-propagating chain reaction and will proceed until the lipid substrate is consumed and the last two remaining radicals combine, or a reaction which terminates it occurs. [3]
In chemistry, initiation is a chemical reaction that triggers one or more secondary reactions. Initiation creates a reactive centre on a molecule which produces a chain reaction. [1] The reactive centre generated by initiation is usually a radical, but can also be cations or anions. [2]
Since nuclear chain reactions may only require natural materials (such as water and uranium, if the uranium has sufficient amounts of 235 U), it was possible to have these chain reactions occur in the distant past when uranium-235 concentrations were higher than today, and where there was the right combination of materials within the Earth's crust.