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Article: Control Mechanisms
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- Biology
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CopyrightCOPYRIGHT 2002 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Control Mechanisms
The cell possesses an extraordinary array of
enzymes
, each specialized to carry out an important function in the cell. However, in many cases it is critical that the enzymes only be active at certain times and not others. For example, the digestive enzymes secreted by cells lining the stomach and intestine must only be active once they have been secreted and not before. If they were active prior to secretion they would degrade the
proteins
within the very cells that synthesized them. Or consider the enzymes that carry out the many activities of cell division. If these are not held in tight control, a cell will divide inappropriately and may become cancerous.
Thus, ...