NDLI: The Minimal Autopoietic Unit

Content Provider	Springer Nature Link
Author	Luisi, Pier Luigi
Copyright Year	2015
Abstract	It is argued that closed, cell-like compartments, may have existed in prebiotic time, showing a simplified metabolism which was bringing about a primitive form of stationary state- a kind of homeostasis. The autopoietic primitive cell can be taken as an example and there are preliminary experimental data supporting the possible existence of this primitive form of cell activity.The genetic code permits, among other things, the continuous self-reproduction of proteins; enzymic proteins permit the synthesis of nucleic acids, and in this way there is a perfect recycling between the two most important classes of biopolymers in our life. On the other hand, the genetic code is a complex machinery, which cannot be posed at the very early time of the origin of life. And the question then arises, whether some form of alternative beginning, prior to the genetic code, would have been possible: and this is the core of the question asked.Is something with the flavor of early life conceivable, prior to the genetic code?My answer is positive, although I am too well aware that the term “conceivable” does not mean that this something is easily to be performed experimentally.To illustrate my answer, I would first go back to the operational description of cellular life as given by the theory of autopoiesis. Accordingly, a living cell is an open system capable of self-maintenance, due to a process of internal self-regeneration of the components, all within a boundary which is itself product from within.This is a universal code, valid not only for a cell, but for any living macroscopic entity, as no living system exists on Earth which does not obey this principle. In this definition (or better operational description) there is no mention of DNA or genetic code. I added in that definition the term “open system”-which is not present in the primary literature (Varela, et al., 1974) to make clear that every living system is indeed an open system-without this addition, it may seem that with autopoiesis we are dealing with a perpetuum mobile, against the second principle of thermodynamics.Now consider the following figure (Fig. 1). It represents in a very schematic form a cell, as an open system, with a semipermeable membrane constituted by the chemical S, which permits the entrance of the nutrient A and the elimination of the decay product P. A is transformed inside the cell into S by a chemical reaction characterized by k$_{gen}$, and S can be transformed into P by the reaction k$_{dec}$. The two reactions actually may represent two entire families of reaction, in the sense that one can envisage several A and several S and several P.
Starting Page	335
Ending Page	338
Page Count	4
File Format	PDF
ISSN	01696149
Journal	Origins of Life and Evolution of Biospheres
Volume Number	44
Issue Number	4
e-ISSN	15730875
Language	English
Publisher	Springer Netherlands
Publisher Date	2015-01-14
Publisher Place	Dordrecht
Access Restriction	Subscribed
Subject Keyword	Minimal cell Autopoiesis Origin of life Genetic code Primitive metabolism Life Sciences Astrophysics and Astroparticles Earth Sciences Astronomy, Observations and Techniques Biochemistry
Content Type	Text
Resource Type	Article
Subject	Medicine Ecology, Evolution, Behavior and Systematics Space and Planetary Science

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Towards an Autopoietic Redefinition of Life

On Prebiotic Ecology, Supramolecular Selection and Autopoiesis

Software Replica of Minimal Living Processes

Metabolic Basis for the Self-Referential Genetic Code

Origin of Life Prize

Which Way to Life?

Two Perspectives on the Origin of the Standard Genetic Code

Paradoxes in the Origin of Life

On the Universality of the Living: A Few Epistemological Notes

The Minimal Autopoietic Unit

Similar Documents

Towards an Autopoietic Redefinition of Life

On Prebiotic Ecology, Supramolecular Selection and Autopoiesis

Software Replica of Minimal Living Processes

Metabolic Basis for the Self-Referential Genetic Code

Origin of Life Prize

Which Way to Life?

Two Perspectives on the Origin of the Standard Genetic Code

Paradoxes in the Origin of Life

On the Universality of the Living: A Few Epistemological Notes

The Minimal Autopoietic Unit