Most of what you think you know about cells may be wrong. Thats the central message of a new book by a University of Washington bioengineering professor who argues that a major premise central to modern cell biology is flawed.

Gerald Pollacks latest work, "Cells, Gels and the Engines of Life: A New, Unifying Approach to Cell Function," published by Ebner and Sons of Seattle, challenges the traditional notion that cells are tiny watery reservoirs held intact by membranes that keep cell contents from mixing with surrounding fluid.

In reality, Pollack says, the membrane isnt key to cell integrity because the water inside the cell isnt normal water its organized by proteins to form a gel. That gel state maintains cellular integrity and offers convincing and simple explanations for a wide array of cell functions. It may even shed light on how cells came into existence when life on earth began.

"If these ideas prove correct, it will turn the field upside down," Pollack said. "Cell biology is built on the premise of aqueous solution behavior, or how things work in normal water with water being a neutral carrier. If thats wrong, then many of the constructs will have to be re-evaluated."

Traditionally, biologists have accepted the idea that cells are surrounded by a relatively impermeable lipid membrane. According to that theory, essential substances enter the cell via selective "channels." To maintain the proper chemical balance, dissolved substances, or solutes, are passed out of the cell via an assortment of "pumps."

Problems quickly arise with such a scenario, however.

How, for example, can channels that allow the entry of large molecules exclude all smaller ones? And pumps require energy. Sodium concentrations are lower inside cells than outside, for instance, and scientists have proposed a sodium pump to help maintain that equilibrium. But the sodium pump alone has been est
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Contact: Rob Harrill
rharrill@u.washington.edu
206-543-2580
University of Washington
24-Apr-2001