Building a flagellum (Introduction)
by David Turell 
, Sunday, June 24, 2012, 16:19 (4333 days ago)
http://youtu.be/Ey7Emmddf7Y- Are you amazed?
Building a flagellum
by xeno6696 , Sonoran Desert, Monday, June 25, 2012, 18:13 (4332 days ago) @ David Turell
http://youtu.be/Ey7Emmddf7Y > -It's only fair to post the common rebuttal. c'mon David, teach the controversy!
- http://m.youtube.com/#/watch?desktop_uri=%2Fwatch%3Fv%3DK_HVrjKcvrU&v=K_HVrjKcvrU&a... -> > Are you amazed?
--
\"Why is it, Master, that ascetics fight with ascetics?\"
\"It is, brahmin, because of attachment to views, adherence to views, fixation on views, addiction to views, obsession with views, holding firmly to views that ascetics fight with ascetics.\"
Building a flagellum
by David Turell , Monday, June 25, 2012, 18:52 (4331 days ago) @ xeno6696
http://youtu.be/Ey7Emmddf7Y > > > > It's only fair to post the common rebuttal. c'mon David, teach the controversy!
Building a flagellum
by David Turell , Tuesday, June 26, 2012, 01:26 (4331 days ago) @ David Turell
http://youtu.be/Ey7Emmddf7Y > > > > > > > It's only fair to post the common rebuttal. c'mon David, teach the controversy!
Building a flagellum
by David Turell , Tuesday, October 27, 2020, 22:01 (1285 days ago) @ David Turell
New steps are added to the fifty known:
https://phys.org/news/2020-10-sweet-flagellar.html
"To build the machinery that enables bacteria to swim, over 50 proteins have to be assembled according to a logical and well-defined order to form the flagellum, the cellular equivalent of an offshore engine of a boat. To be functional, the flagellum is assembled piece by piece, ending with the helix called flagellar filament, composed of six different subunits called flagellins. Microbiologists from the University of Geneva (UNIGE) have demonstrated that adding sugar to the flagellins is crucial for the flagellum's assembly and functionality. This glycosylation is carried out by a newly discovered enzyme FlmG, whose role was hitherto unknown. Based on this observation—which you can read all about in the journal eLife—the researchers followed up with a second discovery published in Developmental Cell. Among the six flagellins of Caulobacter crescentus, the model bacterium in the two studies, one is the special one serving a signaling role to trigger the final assembly of the flagellum.
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"Viollier's research team succeeded in demonstrating that the glycosylation of the six flagellins that make up the filament is essential for the formation and functionality of the flagellum. "To demonstrate this, we first identified the gene that produces the glycosylation enzyme, FlmG. When it's absent, it results in bacteria without flagellum. Secondly, we genetically modified another type of bacterium, Escherichia coli, to express one of the six flagellins, the glycosylation enzyme and sugar producing enzymes from Caulobacter crescentus. All these elements are required to obtain a modified flagellin," adds Nicolas Kint.
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"'The different elements of the flagellum are produced one after the other: the molecules of the base first, then those of the rotor and finally the propeller. The scientific literature indicates that this sequential process is important. However, we don't know how the order of manufacturing the sub-units is controlled ." The researcher and his team focused on the synthesis of the six flagellins, discovering a black sheep among them: a sub-unit that has only 50% sequence homology with the other five. "This sub-unit serves as become a checkpoint protein, a repressive molecular traffic cop restraining the synthesis of the other flagellin proteins," says Professor Viollier. It is present before the synthesis of the other five sub-units, and it acts as a negative regulator. As long as it is present in the cytosol, the synthesis of the other sub-units is prevented. Once the elements of the flagellum are assembled, apart from the filament, the cop is exported to the membrane and thus removed. Then the synthesis of the last five sub-units can then begin. "It is a sensor for the protein synthesis and a component of the flagellar filament at the same time: a dual function that is unique of its kind," says the microbiologist with great enthusiasm."
Comment: An irradicably complex assembly system. How vould this develoop by c hance. Design required.
Building a flagellum
by romansh 
, Tuesday, June 26, 2012, 03:10 (4331 days ago) @ David Turell
http://youtu.be/Ey7Emmddf7Y > Are you amazed?-Yes I am. I have watched this several times. It also amazes me that someone would somehow think this supports ID
Building a flagellum
by David Turell , Tuesday, June 26, 2012, 05:35 (4331 days ago) @ romansh
http://youtu.be/Ey7Emmddf7Y > > Are you amazed? > > Yes I am. I have watched this several times. > It also amazes me that someone would somehow think this supports ID-Do you think something as complex as this could happen totally by chance? I don't and that is how we differ. This implies design and purpose. Aimlessness, no!
Building a flagellum
by xeno6696 , Sonoran Desert, Thursday, June 28, 2012, 12:36 (4329 days ago) @ David Turell
http://youtu.be/Ey7Emmddf7Y > > > Are you amazed? > > > > Yes I am. I have watched this several times. > > It also amazes me that someone would somehow think this supports ID > > Do you think something as complex as this could happen totally by chance? I don't and that is how we differ. This implies design and purpose. Aimlessness, no!-You mistake chance. Evolution doesn't happen by chance, its governed by natural laws. If I expose a culture of e. coli to antibiotics, some will survive. Was it by chance? -The flagellum argument is flawed (and always will be) because you're arguing only with knowledge based on (today's) organisms. It boils down to "I can't think of a way this happened without magic." Akin to what would happen if you took a mayan tribesman and from 900ce and transplanted him into Manhattan. Of course its complex, it's had 200 years of constant development!-The other point is that it has been repeatedly demonstrated that life creates new functions purely by what it comes in contact with. Nothing appears from thin air!-Finally, a last bit that goes back to the antibiotic point: Immune systems work against new unknowns in a manner consistent with unintelligence: it's a shotgun approach. "Let's make every combination of antibody we can and see which one works."-If you think about how primitive this really is--really think about it, you'll understand where I'm driving. The memory of the immune system is quite complex, but the initial strategy is pure, primitive, reactionism. It's also combinatorial. -This brings me back: IDs only argument is against abiogenesis.
--
\"Why is it, Master, that ascetics fight with ascetics?\"
\"It is, brahmin, because of attachment to views, adherence to views, fixation on views, addiction to views, obsession with views, holding firmly to views that ascetics fight with ascetics.\"
Building a flagellum
by David Turell , Thursday, June 28, 2012, 15:04 (4329 days ago) @ xeno6696
You mistake chance. Evolution doesn't happen by chance, its governed by natural laws. If I expose a culture of e. coli to antibiotics, some will survive. Was it by chance?-It was an adaptation by some of the e coli, not evolution, just as the finches adapt their beaks. > > The flagellum argument is flawed (and always will be) because you're arguing only with knowledge based on (today's) organisms. It boils down to "I can't think of a way this happened without magic." Akin to what would happen if you took a mayan tribesman and from 900ce and transplanted him into Manhattan. Of course its complex, it's had 200 years of constant development!-Flagella are in archaea. > > The other point is that it has been repeatedly demonstrated that life creates new functions purely by what it comes in contact with. Nothing appears from thin air!-Yes, epigenetics. How did that capacity develop? It didn't. It was there from the beginning or life would not have survived. > > Finally, a last bit that goes back to the antibiotic point: > Immune systems work against new unknowns in a manner consistent with unintelligence: it's a shotgun approach. "Let's make every combination of antibody we can and see which one works."-Yes, explain the development of the immune response to me. Nothing Darwinian about it. > > If you think about how primitive this really is--really think about it, you'll understand where I'm driving. The memory of the immune system is quite complex, but the initial strategy is pure, primitive, reactionism. It's also combinatorial. -You are supporting me. > > This brings me back: IDs only argument is against abiogenesis. Agreed that it is a mighty argument
Building a flagellum patterns
by David Turell , Tuesday, December 23, 2014, 03:22 (3421 days ago) @ David Turell
The pattern for bacterial flagella are the same, with modification. More pattern evidence:-"Bacteria that can swim propel themselves with corkscrew tails anchored in rotary motors. That may seem surprisingly mechanical for a microbe, but it is a system that has been wildly popular and conserved across billions of years of evolution.-"The basic motor design is a rotating driveshaft embedded in a series of rings that act as stators, the stationary part of a mechanical rotor system. The rings are themselves embedded in the cell wall and cell membranes — the skins of bacterial cells. Most of the rings appear to stabilize the driveshaft, but in one ring near the base (called the MS ring below) are a set of motor proteins that turn the base of the flagellum."
Building a flagellum patterns
by Balance_Maintained , U.S.A., Tuesday, December 23, 2014, 08:38 (3421 days ago) @ David Turell
The pattern for bacterial flagella are the same, with modification. More pattern evidence: > > "Bacteria that can swim propel themselves with corkscrew tails anchored in rotary motors. That may seem surprisingly mechanical for a microbe, but it is a system that has been wildly popular and conserved across billions of years of evolution. > > "The basic motor design is a rotating driveshaft embedded in a series of rings that act as stators, the stationary part of a mechanical rotor system. The rings are themselves embedded in the cell wall and cell membranes — the skins of bacterial cells. Most of the rings appear to stabilize the driveshaft, but in one ring near the base (called the MS ring below) are a set of motor proteins that turn the base of the flagellum."-If we were looking at a drive shaft, we would automatically see design. When we look at a Flagellum, we see random chance. That does not compute.
--
What is the purpose of living? How about, 'to reduce needless suffering. It seems to me to be a worthy purpose.
Building a flagellum patterns
by David Turell , Tuesday, December 23, 2014, 14:53 (3421 days ago) @ Balance_Maintained
> Tony:If we were looking at a drive shaft, we would automatically see design. When we look at a Flagellum, we see random chance. That does not compute.-I agree. The evolutionist's answer is the basic elements that were co-opted can be traced, but they can't describe how the specific complexity was achieved.
Building a flagellum patterns: in bacteria & archaea
by David Turell , Tuesday, September 26, 2017, 20:27 (2412 days ago) @ Balance_Maintained
The construction of a bacterial flagellum and an Archean differ, but both propel:
https://elifesciences.org/articles/27470#abstract
"The molecular composition of the archaellum and of the motor that drives it appears to be entirely distinct from that of the functionally equivalent bacterial flagellum and flagellar motor. Yet, the structure of the archaellum machinery is scarcely known. Using combined modes of electron cryo-microscopy (cryoEM), we have solved the structure of the Pyrococcus furiosus archaellum filament at 4.2 Å resolution and visualise the architecture and organisation of its motor complex in situ. This allows us to build a structural model combining the archaellum and its motor complex, paving the way to a molecular understanding of archaeal swimming motion.
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"Together with a wealth of previous biochemical data, our new structures of the Pyrococcus furiosus archaellar motor complex, the polar cap, the S-layer, and the archaellum itself enable us to build a first model describing the architecture of the archaellum machinery (Figure 7). (go to the website to see the illustration)
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"Filament assembly and rotation is powered by the archaellar motor, which is composed of the fully membrane-embedded FlaJ, a bell-shaped cytosolic complex of FlaI and FlaH and a surrounding cytosolic ring, most likely consisting of FlaC and D/E. This ring was not observed in averages of the archaellar motor complex of Thermococcus kodakarensis, which may either be due to species-dependent structural differences of motor components or the smaller number of particles used for the T. kodakarensis average. In the periplasm, the filament is thought to be coordinated by FlaF. As no densities spanning the entire periplasm are seen in our sub-tomogram average of the motor complex , we suggest that FlaF does not form a continuous conduit that connects the membrane and the outer canopy of the S-layer. Instead, this protein may coordinate the archaellum near the membrane, while the main periplasmic part of the filament is flexibly integrated into the S-layer.
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"In its substance, our model of the archaellum and its motor complex will be universal to all motile Archaea, as the core of the archaellum machinery (FlaA/B, FlaF, FlaG, FlaH, FlaI and FlaJ) is conserved throughout crenarchaeal, euryarchaeal and thaumarchaeal lineages;
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"The ubiquity and conservation of the archaellin/T4 pilin (A/T) blueprint highlights its evolutionary success as an exquisite building block for stable, yet flexible and versatile filaments. The presence of this blueprint in Archaea and Bacteria also raises the intriguing hypothesis that a common A/T-like progenitor protein and filament existed in the last universal common ancestor (LUCA), before these two domains of life diverged more than 3 billion years ago
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"For swimming motion, Bacteria have developed the flagellar machinery, a massive double-membrane spanning macromolecular device that is thought to share a common ancestor with the bacterial type-3 secretion system (Chen et al., 2011; Erhardt et al., 2010). The evolutionary reason for the higher complexity of both, bacterial T4P assembly machines as well as flagellar motors is speculative. However, it may be hypothesised that Bacteria needed to come up with additional protein components for their T4P assembly machinery as well as an entirely different propulsion device as they developed a double membrane, which is, with very few exceptions, not found in Archaea."
Comment: It is not clear, since these two motors are so different, that there is a common ancestor or two ancestors with life starting in more than one place in more than one way. Woese believed the latter.
Building a flagellum patterns: in bacteria & archaea
DAVID’s comment: It is not clear, since these two motors are so different, that there is a common ancestor or two ancestors with life starting in more than one place in more than one way. Woese believed the latter.
Purely for everyone’s information, Darwin allowed for both in his theistic conclusion (later editions of Origin): “There is grandeur in this view of life with its several powers, having been originally breathed by the Creator into a few forms or one…”
Building a flagellum patterns: in human sperm
by David Turell , Tuesday, February 27, 2018, 20:29 (2258 days ago) @ dhw
A new structure has been found in the tail of human sperm:
https://www.sciencedaily.com/releases/2018/02/180220124544.htm
"Human sperms are incredibly important for our reproduction. It would therefore be easy to assume that we have detailed knowledge of their appearance. However, an international team of researchers has now identified a completely new nanostructure inside sperm tails, thanks to the use of cryo-electron tomography.
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"A highly effective tail is needed in order for a sperm to be able to swim, and for an egg to be fertilised.
"The tail is a highly complex machine that consists of around a thousand different types of building blocks. The most important of these are called tubulins, which form long tubes (microtubules). The tubes are found inside the sperm tail.
Thousands of motorproteins -- molecules that can move -- are affixed to these tubes. By being fixed to one microtubule and "walking on" the adjacent microtubule, the motorproteins in the sperm tail pull and the tail bends, enabling the sperm to swim.
"'It's actually quite incredible that it can work," adds Johanna, who led the study. "The movement of thousands of motorproteins has to be coordinated in the minutest of detail in order for the sperm to be able to swim."
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"When we looked at the first 3D images of the very end section of a sperm tail, we spotted something we had never seen before inside the microtubules: spiral that stretched in from the tip of the sperm and was about a tenth of the length of the tail."
"What the spiral is doing there, what it consists of and whether it is important in order for sperms to swim are questions that the research team will now focus on answering.
"'We believe that this spiral may act as a cork inside the microtubules, preventing them from growing and shrinking as they would normally do, and instead allowing the sperm's energy to be fully focussed on swimming quickly towards the egg," says Davide Zabeo, the lead PhD student behind the discovery."
Comment: The tail is just like a bacterial flagellum. Is this another evidence of convergence? Probably. How sexual reproduction evolved is totally unknown. Not by chance; it is way too complex and requires design of the two sexes to match in all their sexual formations and activities.
Building a tough flagellum in human sperm
by David Turell , Monday, March 25, 2019, 00:33 (1868 days ago) @ David Turell
This article describes what a human sperm must overcome to fertilize an egg:
https://cosmosmagazine.com/mathematics/mathematicians-solve-the-mystery-of-human-sperm-...
" And now, our new research has discovered what gives human sperm the strength to succeed in the race to fertilise the egg – and it’s all to do with their tails.
"In the reproductive tract, sperm encounter a complex chemical and physical landscape. A sperm must escape the deadly acids of the vagina, penetrate the thick cervical mucus barrier – this is around a hundred times thicker than water – not get trapped in a cervical crypt that leads to nowhere, endure uterine contractions, to eventually find the tiny opening that leads to the oviducts – the tube through which an egg passes from an ovary. This is all while being attacked in the uterus by white blood cells.
"This all takes place before a sperm can penetrate another thick protective layer that surrounds the egg. All this may sound excessively difficult for the tiny sperm, but these barriers are there for protection – the uterus is designed to receive a baby, and the sperm could be an invading force carrying diseases.
"Our research has discovered that it is a reinforced outer layer which coats the tails of human sperm that gives them the strength to make the powerful rhythmic strokes needed to break through this jelly-like cervical mucus blockage.
"Sperm tails – or flagella – measure just the breadth of a hair in length and are incredibly complex. So to find out more about how they work, we used a virtual sperm model to compare the tails of sperm from humans and other mammals (which fertilise inside the body) with sperm from sea urchins (which fertilise in open water outside the body).
"We found that although the tails of sea urchin and human sperm share the same bendy inner core, it seems that the tails of sperm in mammals may have evolved a reinforcing outer layer. This outer layer, or “cape”, gives them the exact amount of extra strength and stability needed to overcome the thick fluid barrier they come up against in internal fertilisation.
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"Sperm tails – or flagella – measure just the breadth of a hair in length and are incredibly complex. So to find out more about how they work, we used a virtual sperm model to compare the tails of sperm from humans and other mammals (which fertilise inside the body) with sperm from sea urchins (which fertilise in open water outside the body).
"We found that although the tails of sea urchin and human sperm share the same bendy inner core, it seems that the tails of sperm in mammals may have evolved a reinforcing outer layer. This outer layer, or “cape”, gives them the exact amount of extra strength and stability needed to overcome the thick fluid barrier they come up against in internal fertilisation.
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"Of course, we don’t know which adaptation came first, the stronger sperm or the cervical mucus – or whether they co-evolved."
Comment: The authors comment just above is the key issue. Co-evolving by chance is impossible, but appearing together by design is a requirement. The point that the uterus has to have those protection is obvious.