Well maybe. I think there is plenty of opportunity inbasic organic chemistry to form coated water droplets that have sufficientintegrity to cook up something strange. Alsorecall the work done mixing elementary chemicals in ice fractures fordecades. Clay itself is certainly usefuland suggestive since it is degraded volcanic ash which contains a lot of solidcrystalline acids to act as hammer and forge to produce more complex molecules.
My point is that a clay particleis capable of strongly inducing chemical reactions. Thus it is a natural driver for the creationof a protocell, but more like a catalyst than a structural template.
I think we are on the right trackto experimentally produce protocells that are able to mimic some of the key functionsof a cell.
Clay-Armored Bubbles May Have Formed First Protocells
by Staff Writers
Fatty-acid liposomes compartmentalize inside a clay vesicle. Credit:Photo courtesy of Anand Bala Subramaniam, Harvard School of Engineering
A team of applied physicists at Harvard's
The research, published online this week in the journal Soft Matter,shows that clay vesicles provide an ideal container for thecompartmentalization of complex organic molecules.
The authors say the discovery opens the possibility that primitivecells might have formed inside inorganic clay microcompartments.
"A lot of work, dating back several decades, explores the role ofair bubbles in concentrating molecules and nanoparticles to allow interestingchemistry to occur," says lead author Anand Bala Subramaniam, a doctoralcandidate at SEAS.
"We have now provided a complete physical mechanism for thetransition from a two-phase clay-air bubble system, which precludes anyaqueous-phase chemistry, to a single aqueous-phase clay vesicle system,"Subramaniam says, "creating a semipermeable vesicle from materials thatare readily available in the environment."
"Clay-armored bubbles" form naturally when platelikeparticles of montmorillonite collect on the outer surface of air bubbles underwater.
When the clay bubbles come into contact with simple organic liquidslike ethanol and methanol, which have a lower surface tension than water, theliquid wets the overlapping plates. As the inner surface of the clay shellbecomes wet, the disturbed air bubble inside dissolves.
The resulting clay vesicle is a strong, spherical shell that creates aphysical boundary between the water inside and the water outside. Thetranslucent, cell-like vesicles are robust enough to protect their contents ina dynamic, aquatic environment such as the ocean.
Microscopic pores in the vesicle walls create a semipermeable membranethat allows chemical building blocks to enter the "cell," whilepreventing larger structures from leaving.
Scientists have studied montmorillonite, an abundant clay, for hundredsof years, and the mineral is known to serve as a chemical catalyst, encouraginglipids to form membranes and single nucleotides to join into strands of RNA.
Because liposomes and RNA would have been essential precursors toprimordial life, Subramaniam and his coauthors suggest that the pores in theclay vesicles could do double duty as both selective entry points and catalyticsites.
"The conclusion here is that small fatty acid molecules go in andself-assemble into larger structures, and then they can't come out," saysprincipal investigator Howard A. Stone, the Dixon Professor in Mechanical andAerospace Engineering at Princeton, and a former Harvard faculty member."If there is a benefit to being protected in a clay vesicle, this is anatural way to favor and select for molecules that can self-organize."
Future research will explore the physical interactions between theplatelike clay particles, and between the liquids and the clay. The researchersare also interested to see whether these clay vesicles can, indeed, be found inthe natural environment today.
"Whether clay vesicles could have played a significant role in theorigins of life is of course unknown," says Subramaniam, "but thefact that they are so robust, along with the well-known catalytic properties ofclay, suggests that they may have had some part to play."
Clay-armored bubbles may have formed first protocells
February 7, 2011
Fatty-acid liposomes compartmentalize inside a clay vesicle. Credit:Photo courtesy of Anand Bala Subramaniam, Harvard School of Engineering
(PhysOrg.com) -- A team of applied physicists at Harvard's School of Engineering and Applied Sciences (SEAS), Princeton , andBrandeis have demonstrated the formation of semipermeable vesicles frominorganic clay.
The research, published online this week in the journal Soft Matter, showsthat clay vesicles provide an ideal container for the compartmentalization of complex organicmolecules.
The authors say the discovery opens the possibility that primitivecells might have formed inside inorganic clay microcompartments.
"A lot of work, dating back several decades, explores the role ofair bubbles in concentrating molecules and nanoparticles toallow interesting chemistry to occur," says lead author Anand BalaSubramaniam, a doctoral candidate at SEAS.
"We have now provided a complete physical mechanism for thetransition from a two-phase clay–air bubble system, which precludes anyaqueous-phase chemistry, to a single aqueous-phase clay vesicle system,"Subramaniam says, "creating a semipermeable vesicle from materials thatare readily available in the environment."
"Clay-armored bubbles" form naturally when platelikeparticles of montmorillonite collect on the outer surface of air bubbles underwater.
When the clay bubbles come into contact with simple organic liquidslike ethanol and methanol, which have a lower surface tension than water, theliquid wets the overlapping plates. As the inner surface of the clay shellbecomes wet, the disturbed air bubble inside dissolves.
The resulting clay vesicle is a strong, spherical shell that creates aphysical boundary between the water inside and the water outside. Thetranslucent, cell-like vesicles are robust enough to protect their contents ina dynamic, aquatic environment such as the ocean.
The authors' schematic of clay vesicle formation, showing a cut-awayview of the clay shell and dissolving bubble at the top, and a view of thewater-air interface at the bottom. Credit: Image courtesy of Anand BalaSubramaniam, Harvard School of Engineering
Microscopic pores in the vesicle walls create a semipermeable membranethat allows chemical building blocks to enter the "cell," whilepreventing larger structures from leaving.
Scientists have studied montmorillonite, an abundant clay, for hundredsof years, and the mineral is known to serve as a chemical catalyst, encouraginglipids to form membranes and single nucleotides to join into strands ofRNA.
Because liposomes and RNA would have been essential precursors toprimordial life, Subramaniam and his coauthors suggest that the pores in theclay vesicles could do double duty as both selective entry points and catalyticsites.
"The conclusion here is that small fatty acid molecules go in andself-assemble into larger structures, and then they can't come out," saysprincipal investigator Howard A. Stone, the Dixon Professor in Mechanical andAerospace Engineering at Princeton, and a former Harvard faculty member."If there is a benefit to being protected in a clay vesicle, this is anatural way to favor and select for molecules that can self-organize."
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This SEM image shows the exterior surface of a clay vesicle. Photocourtesy of Anand Bala Subramaniam.
Future research will explore the physical interactions between the platelikeclay particles, and between the liquids and the clay. The researchers are alsointerested to see whether these clay vesicles can, indeed, be found in thenatural environment today.
"Whether clay vesicles could have played a significant role in theorigins of life is of course unknown," says Subramaniam, "but thefact that they are so robust, along with the well-known catalytic propertiesof clay, suggests thatthey may have had some part to play."
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