ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: monokekie on April 06, 2010, 09:12:25 pm
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Why are prokaryotic cells able to tolerate extreme temperatures?
thanks
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not all are. some bacteria can live in high temperatures(eg hot springs) cuz their proteins/enzymes have a high optimal temperature, in others, the proteins required to sustain life would be
destroyeddenatured..
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not all prokarytoes can tolerate extreme temperatures
u have psychrophiles, psychrotrophs, mesophiles, thermophiles and hyperthermophiles
so theres a different ranges of temperatures that microbes can grow
thermophiles grow at optimal temperatures between 55-65 degrees and can do so because of its properties... they contain heat stable enzymes, heat stable proteins which have hydrophobic interiors, more hydrogen bonding and other noncovalent bonds to strengthen the structure, more resistanct amino acids.. like proline to make polypeptides less flexible, they have chaperone proteins that stabilize the proteins, the cell membrane is temperature stable- more saturated, more branched and higher molecular weight
psychrophiles have optimal temperature below 15 degrees ... they have high levels of unsaturated fatty acids in their cell membranes
yeah so they can tolerate these extreme temperatures because their machinary have adapted over a long time to these conditions and their proteins etc are more stable at these temperatures...
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arhh kayy, extreme optimal temperatures of enzymes stablises the cell functions, thanks again ppl :D