Science Forums: Psycho - Viewing Profile - Science Forums

There is another website called Overview of Krebs-Reactions Electron Transport and Oxidative...

It explains the need for oxygen as an electron acceptor is the sole reason that we breathe air

jeb.biologists.org/content/210/12/i.2 The oxygen uptake in mitochondria is another website. Do you want more?

I think the problem we are having in communication is how we have a different viewpoint of microbes. Is your opinion of microbes is that they are biochemical conversion machines or something similiar to that?

It explains the need for oxygen as an electron acceptor is the sole reason that we breathe air

[modnote]Seriously? Psycho, you're not a new member here. You already know our code of conduct. Being rude doesn't add credibility to your posts, and makes it extremely hard to read what you are writing. It's also against the rules.

If you guys think other posters warrant the attention of staff, use the report button. Lowering yourselves to the level of rudness will just make us respond to the civility issue rather than a potentially more important underlying issue.


Tone it down, please. [/modnote]

The website is called The Mitochondrial and Metabolic Disease Center and this is where one of my sources explains what I said above.

My digestive system is inside my body, maybe yours isn't but everybody else does.

Well, it told me I had to pay for the article, and I have no reason to think that source is right over an archive of professional scientists and editors with information provided by the most famous museum in America, and it's not famous for being wrong.

Here's the deal: You have your non specific "journal entries" as well as stuff from the infamous wikipedia, and you expect me to believe that over a 65$ book that had a lot of work put into it, more than a few websites and BBC.

That journal entry simply states it is most common for those animals to be in those lower temperatures, which means even according to that article its possible for those worms to survive higher temperatures but for only brief periods of time. If that is the case, it would be fine according to that quote form my book as it does not specify how long those worms stay in vents.

Temperature is one of the most important environmental factors that governs a species' distribution. Some highly specialized prokaryotes can grow at temperatures above 113 °C (ref. 1), but eukaryotes appear less versatile2 and do not normally occur above 55 °C. Here we show that a colony-dwelling polychaete worm, inhabiting deep-sea hydrothermal vent chimneys, regularly experiences temperatures above 80 °C and a thermal gradient of 60 °C or more over its body length.

Active deep-sea hydrothermal vents typically contain areas of high temperature flow (above 300 °C) which are essentially abiotic. Associated with and peripheral to these hot sites are cooler (below 100 °C) diffuse flow regions where mixing with ambient seawater (2 °C) occurs. The thin tube dwellings of the Pompeii worm (Alvinella pompejana; Fig. 1) form thick, heavily channelled structures along the outer walls of vent 'chimneys' created by an accumulation of metal sulphides. Although these worms spend most of their time in the tubes with their gills and buccal structure extended from the tube opening, individuals make regular excursions of up to 1 m to feed on free-living filamentous bacteria growing on the outer surface of the colony.
We deployed self-recording time-lapse temperature probes from the research submersible DSV Alvin at high-temperature chimneys located at the M-Vent site (9° 50.6' N, 104° 17' W) within the Axial Summit Caldera on the East Pacific Rise (EPR) during November 1995 and April 1996. M-Vent is one of three active chimneys, 5-7 m tall, from which intense diffuse vent fluids emerge through densely populated Pompeii worm colonies.

On each dive we positioned a specially designed time-lapse temperature logger (the 'Mosquito'), containing a 20-cm-long titanium probe (0.75 cm diameter), with its temperature sensor adjacent to a Pompeii worm's tail (Fig. 2a). We placed two further temperature recorders adjacent to the tube of interest. We chose completely intact worm tubes, to avoid temperature sampling where the hydrodynamic conditions of the colony might have been altered; we also monitored unoccupied tubes. In all cases resident worms displayed normal behaviour before, during and after deployment of the temperature recorders. The loggers were calibrated before and after each dive. We also made real-time temperature measurements with Alvin's low-temperature probe (0-60 °C range).
In six independent surveys, temperatures recorded 6-8 cm within the worm tubes averaged 68plusminus6.33 °C (meanplusminuss.d.), with frequent spikes exceeding 81 °C (Fig. 2b). The external temperatures were variable, depending on the placement of the in situ recorders and the submersible's low-temperature probe. Measurements made at the tube openings averaged 22plusminus2.5 °C; thus, a temperature gradient of up to 60 °C exists along the length of the worm's body. These measurements were consistent with long- and short-term measurements taken near Pompeii worm colonies at several different EPR sites3,4. No temperature differences were detected between occupied and unoccupied tubes.

A Pompeii worm has survived short exposure to 105 °C (ref. 5); however, this was outside the worms' natural habitat. Our data demonstrate unambiguously that Pompeii worms inhabit an environment with an unprecedented temperature gradient of up to 60 °C. This gradient, although somewhat dynamic, is remarkably uniform over a period of hours. Such a consistent and pronounced gradient over the length of a single worm establishes A. pompejana as the most eurythermal (tolerant of wide temperature range) organism on record. Moreover, the 81 °C temperature at the posterior of the worm suggests that this is also the most thermotolerant metazoan known.

The most thermotolerant and eurythermal eukaryote previously described is the Sahara Desert ant Cataglyphis, which forages under the midday sun at temperatures nearing 55 °C and remains underground for the rest of the day while the temperature rarely drops below 20 °C (ref. 6). These conditions are not as extreme as those experienced by the Pompeii worm.
Several studies have proposed that the Pompeii worm tube might be an efficient barrier against the thermal effect of the diffusing fluid3,7. Other researchers have proposed active ventilation or convective cooling as mechanisms to minimize the thermal exposure of the worm3,8. The present study suggests that the tubes actually channel the hot diffuse flow fluids over the worm's body, maintaining a continually flushed high-temperature environment.

How the Pompeii worm's physiology has adapted to function under such an extreme temperature gradient has yet to be determined. It is also unclear how a metazoan's cytoskeletal proteins, chromosomes, nucleic acid processing machinery and other macromolecules, previously thought to be the thermally limiting components of multicellular eukaryotes, can function at temperatures above 80 °C. Recent interest in the Pompeii worm has focused on a unique assemblage of symbiotic filamentous proteobacteria that cover the dorsal surface of the animal9,10. Like their hosts, these bacteria are positioned within this extreme thermal gradient and survive the same high-temperature environment laden with heavy metals and hydrogen sulphide. Studies of the worm and its associated microflora afford a unique opportunity to discover the biochemical adaptations that allow organisms to thrive in such an extreme thermal regime.