Ask A Scientist© Molecular Biology Archive

name       Anna
status     educator
age        50s

Question - I would like to know more about hemocyanin and hemerythrin
and how they work relative to hemoglobin.

Anna,
You ask an interesting & important question. The chemicals you list belong
to the family of oxygen-binding proteins and correlate very nicely with the
evolutionary branching of different groups of animals. For more detailed
information on their molecular biology, try, for example, the name of any
one of them on Altavista or Yahoo web search, or use "oxygen-binding
proteins" in quotation marks.
Mother Nature plays with different variations on structural themes to
accommodate common and then divergent functions; in this case oxygen-binding
for respiration constitutes the common function. Iron-based molecules in
that group bear the prefix "hem-" or "hemo-". Other oxygen-binding proteins
in some invertebrates evolved branches that use other metal atoms in their
cores.
I hope that addresses the central issues of your question.
CED

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