Life is chemistry plus information

Abstract

In contemporary biology, the predominant paradigm is that life is chemistry. This means that all biological processes could be reduced to physicochemical processes. Some scientists have argued that life is chemistry plus information, but this ontological claim has not yet been proven. This paper first defines biological information through the decoding process, in which molecular machines such as membrane receptors and ribosomes connect signs to objects. Experiments have shown that molecular machines provide specific mechanisms to unidirectionally connect extracellular signals to intracellular second messengers in signal transduction, and unidirectionally link mRNAs to proteins in genetic information. However, I point out that the unidirectionality or irreversibility of biological information violates the (microscopic) time-reversal symmetry in physical laws and the principle of microscopic reversibility in chemistry. Genetic information also breaks the translational symmetry in physical laws, since the role of nucleotide triplets in translation depends on their position in mRNA. Therefore, biological information is non-physicochemical and differs ontologically from chemistry. This means that the paradigm in biology should be that life is chemistry plus information, rather than that life is merely chemistry. The paradigm of “life is chemistry plus information” succinctly explains that biological information provides an arrow of time in living organisms and why living and nonliving things are so different.