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Topic: Protocell


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In the News (Sun 15 Nov 09)

  
  Self-Other Organization:
Since protocell replication is accomplished through an autocatalytic process rather than decoding of a genetic template, change accumulated over the course of a lifetime is not wiped out at the end of each generation but drawn into the lineage.
However, ‘death’ of a protocell goes unnoticed; concretely there is not much to distinguish a ‘dead’ protocell from a ‘living’ one except one continues to spawn replicants and the other doesn’t.
Indeed, to the extent that the state of a protocell at a particular point in time reflects its composition of polymers and their internal pattern of catalysis, its dynamics can be described by recourse to self-organization.
www.vub.ac.be /CLEA/liane/papers/soo.htm   (6067 words)

  
 Index
Protocell Assembly(PAs) is a Los Alamos National Laboratory LDRD-DR sponsored project, which seeks to assemble a minimal self-replicating molecular machine.
The technical team for the Protocell Assembly (PAs) project consists of scientists at Los Alamos together with scientists at other US and European institutions.
An international protocell knowledge repository environment can be found at www.protocell.org.
protocells.lanl.gov   (300 words)

  
 Peering into Darwin's Black Box. Origins & Design 20:1 Feature Article
Protocell theory is a popular theory often proposed to explain how biochemical complexity arose in living cells by completely natural, evolutionary processes.
Protocell theorists propose that the bacterial flagellum evolved gradually by natural selection (Loomis, 1984), implying that such complex mechanisms are late developments in the evolution of bacteria and would not have been present in early protocells.
If, however, the protocell is a self-reproducing cell, as the theory suggests, then several essential cell functions that appear to be complex in contemporary cells would have to be present even in the early protocell.
www.arn.org /docs/odesign/od201/peeringdbb201.htm   (9279 words)

  
 A Model of the Protocell   (Site not responding. Last check: 2007-11-02)
Indeed, for different models of protocells, different sets of laboratory experiments and computer simulations are significant.
This raises a distinct possibility that protocells initially represented the ``pre-RNA world'' in which cellular functions were performed, probably with low efficiency and specificity, by simple molecules, including possible precursors to proteins (i.e.
A corollary to this argument is that special attention should be focused on unique properties of protocells that distinguish them from other environments and, in particular, on the role of membranes.
exobiology.nasa.gov /ssx/biomod/1996_pac_symp_biocomp/node2.html   (880 words)

  
 THE EVOLUTION OF LIFE
The protocells may appear completely passive in that their functions are completely determined by chemical laws, while cells, such as an amoeba, seem to act purposefully to seek out nutrients and metabolize them.
Those protocells which first developed the capability for movement had a distinct advantage in obtaining nutrients over the protocells which were dependent on currents of water for moving them to places where there were nutrients.
Therefore, fairly early in the evolution of the protocell a subsystem had to be developed for distributing nutrients to all parts of the protocells in a balanced way.
www.see.org /e-ct-2.htm   (17794 words)

  
 Ch. 20
A protocell is a cell-like structure with a lipid-protein membrane and carries on energy metabolism.
The protocell likely was a heterotrophic fermenter living on the organic molecules in the organic soup that was its environment; this suggests heterotrophs preceded autotrophs.
Once the protocell was capable of reproduction, it became a true cell and biological evolution began.
howard.nebrwesleyan.edu /hhmi/fellows/awasmoen/mader20.html   (2799 words)

  
 Research & Technology Report 1999   (Site not responding. Last check: 2007-11-02)
Two properties strongly affected the ability of the protocell to evolve: the balance between the probability that a peptide is an efficient protease and the probability that it is an efficient ligase, and the strength of the preference toward the hydrolysis of unstructured peptides.
Although in both models the overall catalytic capabilities of the test protocell increase, when the probability of forming efficient ligases is reduced (dashed line), so is the final catalytic capability of the protocell.
In this figure, almost all improvement in the catalytic capabilities of the test protocell is eliminated when the preference for the hydrolysis of unstructured the reference model (solid line).
ameslib.arc.nasa.gov /randt/1999/science/exobio7.html   (901 words)

  
 [No title]
Theoretical models and experimental data support the idea that simple protocells should be obtainable from a simple systems of coupled reactions dealing with the three previous components.
Beyond the specific properties displayed by the PACE protocell design, there is a whole range of possible scenarios of protocell assembly that could be explored using this framework.
The large-scale simulation of living protocells also allows a deep exploration of their computational and evolutionary potential, thus providing a powerful framework for future development within the emerging field of living technology.
complex.upf.es /~ricard/PACEsite   (2229 words)

  
 CONTINUITIES AND DISCONTINUITIES iN THE REALMS OF LIFE AND MIND   (Site not responding. Last check: 2007-11-02)
-from a protocell to the universal ancestor and the first prokaryotic cell,up to the today bacteria,there are only chemical structural processes,and thus all these organisms are structural machines.
A protocell is not yet alive,but it represents an important structural step for preparing the living cell.By physico-chemical evolution the protocell becomes the universal ancestor of all biological cells,a primordial prokaryote, containing macromolecules of nucleic acides and proteins.Morowittz considers that these macromolecules evolved inside the protocell and not so much outside it.
The only phenomenon which has to be taken into consideration is the mental process,because he is a reality to be recognized in connection with the human mind,and therefore with life in general.If this general process is recognized,then it follows the necessity to recognize a substratum for this process,which cannot be purely structural.
www.racai.ro /MD-Web/MOROWITZ.html   (1385 words)

  
 [No title]   (Site not responding. Last check: 2007-11-02)
The protocell might be an exception to this rule, therefore implying that one of fundamental principles of current living things might have appeared later in evolution.
However, the protocell has about half the energy-to-biomass efficiency of an actual unicell, so that the metabolic rate of the protocell is estimated to be 12*10
W. This difference in efficiency between the protocell and an actual cell would imply that allometric scaling in biology appeared later in evolution, as a process of optimization of nutrient transport.
complex.upf.es /~montoya/PACE_allometries_stoich.htm   (965 words)

  
 Citebase - Protocell Self-Reproduction in a Spatially Extended Metabolism-Vesicle System   (Site not responding. Last check: 2007-11-02)
Authors: Macia, Javier; Sole, Ricard V. Cellular life requires the presence of a set of biochemical mechanisms in order to maintain a predictable process of growth and division.
In this paper we present a simple biochemically and physically feasible model of cell replication involving a discrete semi-permeable vesicle with an internal minimal metabolism involving two reactive centers.
The model can be used as a basic framework to model whole protocell dynamics including more complex sets of reactions.
citebase.eprints.org /cgi-bin/citations?id=oai:arXiv.org:q-bio/0511041   (196 words)

  
 Steve Quayle News Alerts
Instead the protocell is glued together by a clump of fatty-acid molecules (“kind of like a used wad of chewing gum,” Rasmussen explains).
An adult protocell will measure merely five to 10 nanometers across; in comparison, M. genitalium, the organism Venter and his team are working with, is between 200 and 250 nanometers.
The protocell, he says, could be designed to sense when it encounters a particular type of tissue in the body and then to dump its cargo.
www.stevequayle.com /News.alert/05_Genetic/050206.life.built.html   (4055 words)

  
 Chapter 19: Origin and History of Life   (Site not responding. Last check: 2007-11-02)
A protocell would have with a lipid-protein membrane and carry on energy metabolism.
If a protocell was a heterotrophic fermenter living on the organic molecules in the organic soup that
Once the protocell contained DNA genes, or RNA molecules, it was a true cell.
www.sirinet.net /~jgjohnso/apbio19.html   (2756 words)

  
 ALIFE VI abstract: Computational Models for the Formation of Protocell Structures   (Site not responding. Last check: 2007-11-02)
It is generally believed that during prehistoric evolution phospholipid molecules first self-assembled into protocell structures such as micelles, monolayer and bilayer structures, some of which eventually evolved into cell membranes.
This model can be used to study, at the microscopic level, the self-assembly of different protocell structures in the evolutionary process and the impact of environmental conditions on the formation of these structures.
It may be further generalized to simulate the formation of other, more complex structures of amphiphilic molecules such as monolayer and bilayer aggregates.
alife6.alife.org /abstracts/AC15.html   (322 words)

  
 All Protocell messages   (Site not responding. Last check: 2007-11-02)
Does anyone have info about protocell, good or bad feedback, my niece is taking this and having good results, however my friend has just been diagnosed with cancer and is considering taking it and would like to speak with someone else who may have taken it.
After his week off of his chemo treatment, it was time to start a 2 week run with it.
Cantron and Protocel are some of the most powerful antioxidants so they can be used as a preventative, but some people don’t like them because they are not natural treatments.
www.cancercompass.com /message-board/message/all,1835,0.htm   (1325 words)

  
 Mader: Biology - Chapter 21 Outline   (Site not responding. Last check: 2007-11-02)
The chemical evolution of the protocell and experiments supporting this occurrence, the fossil record, continental drift, and major geological periods are topics covered in this chapter.
In this chapter outline, the learning objectives and the selected key terms are given for each major head in the chapter.
Describe differences between the protocell and a true cell.
www.mhhe.com /biosci/genbio/maderbiology/chaptools/ch21outline.html   (183 words)

  
 AnandTech   (Site not responding. Last check: 2007-11-02)
Protocell has been a member of the AnandTech Community since Saturday, March 15, 2003.
Protocell has posted 79 messages to the Community, an average of 0 posts per day.
Protocell is currently not logged in to the Community.
www.anandtech.com /myanandtech.html?member=116778   (138 words)

  
 A Stefan problem for a protocell model (ResearchIndex)
1 Physico-chemical model of protocell (context) - Schwegler, Tarumi et al.
1 A nonlinear treatment of the protocell by boundary layer app..
Reconstruction of a 2-D binary obstacle by controlled..
citeseer.ist.psu.edu /361299.html   (320 words)

  
 Abstract for 94PrRoySoc-Protocells   (Site not responding. Last check: 2007-11-02)
I analyze the tradeoff among three correlated traits: competitiveness against other genotypes for resources within hosts (protocells), damage to the host (virulence), and rate of horizontal transmission from one host to another.
My analysis shows that many aspects of parasite and protocell evolution must be studied with the theoretical tools of social evolution.
I discuss extensions that are required for a general theory of symbiosis.
stevefrank.org /abstracts/94PrRoySoc.html   (177 words)

  
 Computational Modeling of Protocell Division: A Spatially Extended Metabolism-Membrane System   (Site not responding. Last check: 2007-11-02)
Second Notice: If you did not reply to the survey on the first round and might have a few moments to help this time, please do the survey.
Abstract: Cellular life requires the presence of a set of biochemical mechanisms in order to maintain a predictable process of growth and division.
It is shown that such a system can effectively lead to a whole cell replication cycle.
www.comdig.org /print_article.php?id_article=23233   (320 words)

  
 Linglan's Research Homepage   (Site not responding. Last check: 2007-11-02)
It is generally believed that during prehistoric evolution phospholipid molecules first self-assembled into protocell structures such as micelles, mono-layer and bilayer structures.
Some of these protocell structures eventually evolved into cell membranes.
There have been various attempts to simulate the self-assembly process by computer programs.
www.opencircuitdesign.com /~linglan/research   (364 words)

  
 Protocells: The Origin of Cellular Life   (Site not responding. Last check: 2007-11-02)
Networked, spherical aggregates of protocells in extra-protocellular thermal protein matrix of SIU-1.
Note the variations that can occur as seen in the following two figures.
Dendritic network of protocells in extra-protocellular thermal protein matrix of SIU-2.
www.siu.edu /~protocell/photos2.htm   (60 words)

  
 Find in a Library: Prebiotic chemistry : from simple amphiphiles to protocell models
Find in a Library: Prebiotic chemistry : from simple amphiphiles to protocell models
Prebiotic chemistry : from simple amphiphiles to protocell models
WorldCat is provided by OCLC Online Computer Library Center, Inc. on behalf of its member libraries.
worldcatlibraries.org /wcpa/ow/726246d21e1da6e0a19afeb4da09e526.html   (85 words)

  
 ECLT - Past Workshops   (Site not responding. Last check: 2007-11-02)
Evolutionary probabilistic design for protocell - Irene Poli, Michele Forlin, Timoteo Carletti, Roberto Serra, Davide De March -
A model for the study of the dynamics of a population of protocells - Roberto Serra, Timoteo Carletti, Irene Poli -
Thread 2: Protocell chemistry - Peter Nielsen, Steen Rasmussen, Günter von Kiedrowski -
bruckner.biomip.rub.de /bmcmyp/Data/ECLT/Public/PASTworkshops.html   (237 words)

  
 VN Boards - Congrats Mirelind on RR9
Date Posted: 3/14 3:08pm Subject: RE: Congrats Mirelind on RR9 - Date Edited: 3/14 3:16pm (1 edits total) Edited By: ProtoCell
This is not the norm but go ahead and think so bro.
Ok Mthod the nS first off slow down and listen carefully bro.
vnboards.ign.com /killibury_cluster/b22956/95627745/p2/?16   (1006 words)

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