Studying
Cell Biology Preface | Introduction to Problem Solving | Problem Sets | Acknowledgments |
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Tetrahymena is a free-living, unicellular, ciliated organism that normally
lives and thrives at 18-22 oC. If these creatures are
suddenly transferred to an environmental temperature of 8 oC,
they die. However, if the temperature is lowered gradually to 8
oC over a period of several days, most survive and continue
to grow, albeit at a slower rate. Many changes characterize the gradual adaptation of these organisms to
lower temperatures. In particular, their amphipathic lipids are
found to contain fatty acids with shorter hydrocarbon chains and more
unsaturated hydrocarbon bonds than found in cells frowing at 18 oC. (10 pts) Discuss specifically how these changes in lipid composition most likely contribute to survival at the lower temperature. |
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