anyone know organism with freely rotating axle??

D

dazzlepecs

Registered Senior Member
I remember there was some single-celled thing that had an apparatus of this sort... Anyone know what im talking about or am i going senile?
 
I do not remeber the name or have ref, but there is at least one tiny organism with a "cork screw tail" (used to "swim") that can continuously rotate many 360 degree turns. I do not know how it moves it / transfers power to it - seems impossible but as no one has informed that organism of this impossibility, it continues to swim around spinning its tail.:bugeye:
 
Billy T said:
I do not remeber the name or have ref, but there is at least one tiny organism with a "cork screw tail" (used to "swim") that can continuously rotate many 360 degree turns. I do not know how it moves it / transfers power to it - seems impossible but as no one has informed that organism of this impossibility, it continues to swim around spinning its tail.:bugeye:
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There are many species which have it. I haven't heard a particularly convincing explanation as to how they move yet either.

It is supposed to be moved by power from moving H+. Someone calculated that this would take ~1000 protons for each turn.

motor.gif


The pink thing is a protein that surrounds that wheel on the inside of the cell for the protons to go through. I'd like to see what the charged ring is supposed to be made of.

That image is just a general proposal though, it hasn't been fully figured out yet. I'm pretty sure there hasn't been a close look at the flagella (they are about 20 nm). In my microbiology class we were looking at observation methods as well as flagella, so I'll ask my professor more and post if there is anything to add.
 
To Enmos:

No, I do not mean a flagellum. As I understand that term (which come the Roman or Greek term to wip, similar to English Flail) there is only a "wagging motion" no rotation. Sperm cells do "flail their way" to the egg, proportionally a longer journey than most people make each day (under their own power, not by car of course) but not even one 360 turn of their tail.
 
Flagellar movement is considered rotary. That's why they hypothesized that "proton turbine".
 
Exhumed said:
Flagellar movement is considered rotary. That's why they hypothesized that "proton turbine".
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I would think that sperm cells are the key to this question. They have the ability to locomote while unattached to their organism. (Perhaps white blood cells also do this, I don't know.) Suspend one in an organ containing a nutrifying liquid medium like blood, stick its little appendage out through a primitive sealed bearing orifice, and let that appendage move around outside the organism. From there, the development of rotary motion would not be much of a challenge. Nor would suspending it in a sealed bearing orifice at both ends. It could become larger, an organ unto itself with an internal blood supply, feeding wheels which could grow out from the axle organ. Presto, organic wheels a la James P. Hogan's Code of the Lifemaker. (Although his alien creatures appear to be mechanical artifacts from our perspective, as do we from theirs.)
 
Interesting :p What did those do in the book?

I assume sperm are the key since they are one of the few who move relatively straight? Most bacteria move nearly randomly, although they have a movement that makes it generally favored for a desirable location, they go in a very indirect path. I don't know about most eukaryotes though.
 
Some flagella are powered by true rotary motion in a little multi-stage motor set up at their base. Thousands of different kinds of beings have such flagella - they are common.

The exact setup varies by organism and situation. Some push, some pull, some merely spin and create current. Some can be rotated both ways - as in certain flagellate algae, that turn "with" the spiral of the flagellum to pull themselves through the water, and reverse the rotation to go "against" the spiral of the flagellum - thereby making a little disorganized tangle of it, interruption the pull - when they want to stop and change direction.

A lay-friendly description of a particular bacterial flagellum, with pictures and diagrams and that all-important video dramatization: http://www.nanonet.go.jp/english/mailmag/2004/011a.html
Nature created a rotary motor with a diameter of 30 nm. Motility of bacteria, such as Salmonella and E. coli with a body size of 1 ~ 2 microns, is driven by rapid rotation of a helical propeller by such a tiny little motor at its base. This organelle is called the flagellum, made of a rotary motor and a thin helical filament that grows up to about 15 microns. It rotates at around 20,000 rpm, at energy consumption of only around 10-16 W and with energy conversion efficiency close to 100%. Prof. Namba’s research group is going to reveal the mechanism of this highly efficient flagellar motor that is far beyond the capabilities of artificial motors.
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Bacterial cells swim actively by rotating a bundle of flagella. The motor switches its direction every few seconds to change the swimming direction of the cells for bacteria to seek better environments. Reversal of the motor rotation causes a structural change of the flagellar filament from the left-handed to the right-handed helical form. This makes the flagellar bundle fall apart, propelling force imbalanced, leading to changes of the swimming direction.
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Basically, the ATP synthase enzyme could be considered a rotary motor as well, requiring 12 protons per revolution to be passed through the system, while it is synthesizing ATP in the same time, with close to 100% efficiency. That would mean that the theoretical net expenditure while idling would be close to zero.
 
Exhumed said:
What did those do in the book?
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They had wheels and all the characteristics we would expect of machinery. To humans they looked exactly like artifacts originally designed by organic creatures using the same kinds of materials we might have available and the same kinds of technologies we might develop in a few more centuries, although no one who studied them could really understand them well enough to say that with certainty. They were self-replicating, with the kicker that their blueprints were divided in half and each creature had halves of two different blueprints, which had to be combined to build a new one. That gave the opportunity for random combination as well as mutation. They had thus evolved far beyond their original "design" and had built their own civilization.

They even had discovered their own "technology" of building "artifacts" that were indistinguishable from very primitive organic tissue. Their "devices" use muscles, nerves, blood, etc. They thought the creatures who had built us were really clever. Each group of creatures thought they had arisen naturally and the other one had been constructed by creatures like themselves.

Or, had each group discovered the secret to abiogenesis on the others' planet?

Code of the Lifemaker by James P. Hogan. One of my all-time favorite books.
 
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flagellum is run by a structure like atpase. it works like a rotary motor, and spins a corkscrew allowing for motility. This is common in many microbes.
 
The animation posted shows a somewhat simplified view that does not really explain the source of the rotating force. I have been told that the hydrogen ions don't just pass through the channel (a), but are actually directed through the rotor (c) as well, and in order to reach the mitochondrion matrix, the proton flow has to shift the rotor some distance in relation to the channel so they could re-enter it and move on. The channel --> rotor --> channel flow causes the rotor to rotate.
 
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