29. In sicklecell anemia, a
hereditary disease,there is
substitution of one amino acid
by another in one of the four
polypeptide chains of
hemoglobin. In this case are
all of the structural levels of
the protein modified?

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In disease there is a change
in the primary protein structure of one
of the chains that form
hemoglobin: the acid glutamic
acid is substituted by the amino acid
valine in the β chain. The
conformation of the molecule in addition
is also affected and modified by this
primary “mistake” and the modification
also creates a different (sickle) shape to
the blood cells.

Modified, sickled, red blood cells
sometimes aggregate and the
peripheral circulation causing tissue
hypoxia and the pain crisis typical of
sickle cell .