In this TLP, you have learnt how the formation of crystals can occur inside cells by cooling or dehydration, and why this is usually fatal to them. The basic theory behind nucleation and crystallization has been introduced, and the water-sucrose system has been described as an approximation to the composition of cell cytosol.
You should appreciate that some plants and animals have adapted in order to avoid crystallization. The three main ways of achieving this are:
- through the formation of a glass.
- through extracellular crystallization (formation of the crystals outside the cell membrane).
- through the use of antifreeze proteins.
- Fletcher, Chemical Physics of Ice, CUP,1970.
- Franks F, Biophysics and Biochemistry at Low Temperatures, CUP, 1985.
- Greenwood G W, Greer A L, Herlach D M, & Kelton K F, Nucleation Control, Phil. Trans. Royal Society (A 361, no 1804, 15 Mar 2003), pp. 403-633.
- Cryobiology - A Short Course
An online course in cryobiology from the University of Calgary. Particularly useful are: chapter 1, which describes biological cells; chapter 6, on freezing as a crystallisation process; and chapter 12, on animal strategies for surviving in cold climates.
- Ice Formation in Higher-Plant Cells
A page describing freeze avoidance in plants on the Physiology Online website.
- Resurrection Plant
This page on the Union County College website describes the Selaginella lepidophylla resurrection plant.
- Nucleation in Metals and Alloys
This section from the online manual for the MATTER project's Materials Science on CD-ROM, gives more in-depth information about nucleation. The page refers to the nucleation of metals, but the same applies for nucleation of ice or minerals in cells.
- Rana sylvatica (wood frog)
This page on the Animal Diversity website of the University of Michigan Museum of Zoology describes the freezing capabilities of the Northern Wood Frog.