Monday, November 16, 2009

How is it that some bacteria live in the hot springs of Yellowstone Park at temperature up as high as 73 C?

another biology Question

How is it that some bacteria live in the hot springs of Yellowstone Park at temperature up as high as 73 C?
Extreme thermophiles have adapted unique ways to surviving harsh conditions. They're enzymes are specially designed to resist denaturing at high temperatures. What's really amazing is their DNA. Extremophile DNA is positively supercoiled (this describes the way it is twisted around itself) which makes it harder to separate the strands. DNA in most other species is negatively supercoiled (meaning it's wound up on itself in the opposite direction as positively supercoiled DNA). Since DNA is the building block of life, it makes sense that you need to be able to protect it from the environment. Extremophiles do just that by positively supercoiling it. It is much more resistant to heat denaturing than other DNA would be, which helps the bacteria to survive.
Reply:http://www.biologynews.net/archives/2006...





Good question.
Reply:Because they are xenophiles
Reply:Hold on to your hats people. Highest temperature where bacteria have been isolated from is 121 degrees C. It is theorised that we may find them up to 140degrees C.





This is possible because they have adapted their enzymes to work at high temperatures. Also the DNA has special chaperone proteins that prevent the DNA from dissociating from the heat. They are truely remarkable organisms. The limit we think will be the temperature at which ATP breaks down on its own accord, and as the primary energy source for all living organsims, that we be catastrophic for them.
Reply:Organisms which live in such high temperatures are known as thermophiles. They can live in such conditions because of their structure. They have special, strong cell walls which can withstand the heat for example. Their enzymes work optimally at those temperatures. Essentially it because of how they have evolved, or more acurately, not.





When Life first appeared on Earth, it was a much hotter place than it is now! As such, originally, all forms of life could live under such conditions, in fact in most cases even hotter. gradually the Earth began to cool, and new life forms appeared which could exist in these new conditions.





Thermophilic bacteria such as those that are found in hot springs are, in evolutionary terms, very very old. Thay haven't really evolved/adapted to live in hot environments as such, they've just stayed the way they were to start with! However, because their structure is specialised to survive hot conditions, if you were to move them, and put them somewhere more 'normal', they would not survive. This is mainly because their enzymes (vital for energy production, replication etc) are designed to work at high temperatures, and will not work at low ones. All bacteria have a certain range of conditions in which they can live. If you take that away from them, they die.

bleeding heart

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