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Lead Poisoning Pathology
Name:
Status: Educator
Grade: 6-8
Location: OH
Country: United States
Date: May 2005
Question:
Our science book tells us that lead poisoning is caused
by the lead fooling cells into thinking that it is magnesium or
calcium. We wanted to know how it fool's the cells into letting it in?
Replies:
"Fools" implies that lead takes an active role in a deception, but another
way of looking at it is the cell is ineffective at distinguishing. Both
lead and calcium can have a +2 charge as ions, and the ionic radius (how
big the ion appears in solution) is somewhat similar. Because of the
similarity, lead ions can easily be transported as though it were
calcium. However, problems arise when some proteins bind the lead more
tightly than they would calcium, altering or stopping the protein function,
thus harming the cell. If it is just a few lead ions, the cell can make
more proteins, but if it is a lot, the cell may not recover and can die.
Some cells encountering higher amounts of lead (or other toxic metals) will
make special proteins especially designed to bind the lead to store it out
of harm's way.
Don
Cellular pumps that are responsible for the absorption of Ca, are tricked
into "thinking" that Pb ions are Ca ions.
Ron Baker, Ph.D.
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Update: June 2012
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