Simple answer: Sometimes the law addresses a valid concern and is applicable to the circumstances which need regulation. Sometimes it doesn't relate to logic at all.
Allosteric regulation and Reversaeble regulation :)
The word regulation is an adjective as well as a noun (regulation football, regulation uniform, etc). Regulatory is another adjective form for the noun regulation.
Regulation is a noun, as in a law or a rule. It is an adjective, as in 'regulation army equipment'
Regulation
Auto-regulation
Army Regulation 530-1 and Army Regulation 25-1
They reduced regulation.
War of the Regulation happened in 1770.
Validity is not precisely the same thing as legality, it has more philosophical implications. A valid law, statute or ordinance would be one that is consistent with the fundamental philosophical principles as well as the constitutional legal framework of the particular society in which it has been enacted.
Up-regulation is where a cell creates more receptor due to little ligand activity. Down-regulation is the opposite. They are caused by intracelluar processes.
Percent Regulation is the regulation expressed as a percentage is a figure of merit used to specify the performance of a voltage regulator.