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I saw a description of the "minimum requirements" for a cell at http://creation.com/origin-of-life in the section called "What are the minimum requirements for a cell to live?" and I'm wondering if this is scientifically accurate - and if not - what are the real requirements?

[note/warning - the link above is to a creationist site - I'm only quoting this source because I'm trying find the science involved and I didn't find other sources talking about all the necessary pieces. I'm not trying to promote creationism with this question so please don't attack the source or me for bringing it. If you can find a non-creationist source which outlines these requirements, I'll be happy to update the question and remove this source.)

In summary it lists the requirements as follows:

  1. cell membrane
  2. way of storing information (DNA)
  3. way of reading 2. to make components needed
    • RNA polymerase
    • gyrases to untwist DNA
    • ribosomes to make proteins
    • (a few others I omitted b/c I don't know if they're really important)
  4. means of creating fuel (ATP synthase)
  5. a means of copying the information for reproduction

The context of the question is similar to Can scientists create totally synthetic life? and a question I wrote What is the most complex biological organism (or precursors) that we have been able to synthesize from raw materials?.

I'm trying to understand what would be involved in making a cell from scratch. Somehow I found this source but I don't know if it's accurate.

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  • $\begingroup$ An even more minimalistic approach would use a single molecule to do the enzymatic job while storing evolvable informations. In this case RNA alone has been proposed as substitute for proteins and DNA in a very minimal cell. In theory also DNA alone could do the same. However the minimal tasks needed to be done: maintain the self (to be compartimentalized), to grow (to have a flux of molecule not in equilibrium), to divide, to maintain the information stably enough to be useful for the next generation and at the same time prone too mutability to evolve. $\endgroup$
    – alec_djinn
    Commented May 24, 2015 at 22:57
  • $\begingroup$ So to make cells from scratch you would need: amphiphilic molecules to form a membrane, a decent mix of simple molecules (sugars, nucleic acids, peptides) that serve as reactant and building blocks for more complex things, some simple catalyzer (metals, minerals, pepetides, aptamers, etc..) to run the reactions, enough energy to maintain lots of reactions running and keep them far from the equilibrium. Of course, lots of time... $\endgroup$
    – alec_djinn
    Commented May 24, 2015 at 23:03
  • $\begingroup$ @alec_djinn - could add you comments as an answer so I could upvote them? $\endgroup$
    – Yehosef
    Commented May 24, 2015 at 23:22
  • $\begingroup$ The website is called creation.com; how ironical :P $\endgroup$
    – WYSIWYG
    Commented May 25, 2015 at 4:40
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    $\begingroup$ I don't think this question makes much sense. Just because many cells living today satisfy that list of "requirements", that doesn't mean it's the only way to arrive at self-reproducing entities. If you define life as self-reproduction, then any molecule that catalyses its own synthesis is "alive". Beyond self-replication, the requirements gets pretty arbitrary. If you for some reason list a lipid membrane as "required", then yes you need some lipids. Otherwise not. $\endgroup$
    – Roland
    Commented May 27, 2015 at 16:30

2 Answers 2

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So, to make cells from scratch you would need: amphiphilic molecules to form a membrane, a decent mix of simple molecules (sugars, nucleic acids, peptides) that serve as reactant and building blocks for more complex things, some simple catalyzer (metals, minerals, pepetides, aptamers, etc..) to run the reactions, enough energy to maintain lots of reactions running and keep them far from the equilibrium. Of course, lots of time...

An even more minimalistic approach would use a single molecule to do the enzymatic job while storing evolvable informations. In this case RNA alone has been proposed as substitute for proteins and DNA in a very minimal cell. In theory also DNA alone could do the same. However the minimal tasks needed to be done: maintain the self (to be compartimentalized), to grow (to have a flux of molecule not in equilibrium), to divide, to maintain the information stably enough to be useful for the next generation and at the same time prone too mutability to evolve.

One more point. Life itself doesn't strictly require to be compartmentalized. You can think of a network of chemical reactions that have the ability to grow, to replicate its components etc but without a cell membrane. However I think that a cell-like form of life is somewhat more likely to happen.

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  • $\begingroup$ Why a down vote? The answer is pertinent and correct... $\endgroup$
    – alec_djinn
    Commented May 26, 2015 at 17:34
  • $\begingroup$ I downvoted because it is basically a list of what is needed in a typical cell, not a minimal cell. Hence it doesn't really address the question. Apologies for not commenting earlier. Happy to upvote after edits. Please ping me. $\endgroup$
    – AliceD ♦
    Commented May 27, 2015 at 14:34
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    $\begingroup$ Well, maybe it was not clear enough but as catalysts I have listed metals, mineral and peptides instead enzymes and a have specified that a mix of simple molecules will be needed, this is what would make a cell 'minimal'.Indeed the difference between a minimal cell and a proper cell is the complexity of its building blocks. So, the minimal cell requires the same basic components of a normal cell, but you may expect to have a simpler version of them (less complex, less diverse, less optimized). $\endgroup$
    – alec_djinn
    Commented May 27, 2015 at 14:54
  • $\begingroup$ Thanks :) good edit and +1 for the RNA enzymatic activity $\endgroup$
    – AliceD ♦
    Commented May 27, 2015 at 14:57
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Cell is the structural and functional unit of life, made up of a small mass of protoplasm delimited by a semi permeable membrane and capable of self reproduction without any living medium. This is a proper definition of cell and the minimal requirements would be all these mentioned here. You can also see cell theory by M.J. Schleiden and Theodor Schwann. But most importantly not only genetic information and membrane are required, most required part will be Cell should be capable of self reproduction without any living medium

Like for example RBC is not called cell cause they can't reproduce themselves. But nerve cell is called cell cause though they are not divisible but in embryonic condition the cell division occurred. Also in case of virus, as they can't reproduce without a host,they can't be called cell. Red blood corpuscles aren't cells have a good proof in this article (check blood trivia part) red blood corpuscle

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  • $\begingroup$ Nucleus in case of eukaryotic. But there should be genetic information in prokaryotic cell. $\endgroup$
    – Demietra95
    Commented May 25, 2015 at 8:23
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    $\begingroup$ You do realize that the 'C' in 'RBC' stands for 'cell'? $\endgroup$
    – fileunderwater
    Commented May 25, 2015 at 11:28
  • $\begingroup$ Good to start with a working definition of a cell though, since it is relatively meaningless to answer this question without one. Are your italicized definition a quote or your own? $\endgroup$
    – fileunderwater
    Commented May 25, 2015 at 11:32
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    $\begingroup$ @fileunderwater Originally it was called Red Blood Corpuscles. $\endgroup$
    – WYSIWYG
    Commented May 25, 2015 at 11:34
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    $\begingroup$ @WYSIWYG Well, in that case there seems to be some disagreements, since the American Society of Hematology at least seems to label them Red Blood Cells. $\endgroup$
    – fileunderwater
    Commented May 25, 2015 at 11:37

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