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Tutorial to help answer the question
Cotransport systems of the intestinal epithelial cells include the_________
in the intestine-facing membrane, the energy requiring _____________
facing the blood, and the ______________, allowing facilitated diffusion
of glucose out of the cell.
||permease, cotransporters, Na+K+
||cotransporters, CFTR, permeases
||Na+K+ ATPase, cotransporters,
||cotransporters, Na+K+ ATPase,
|The diagram illustrates the cotransport system of
our intestinal epithelial cells.
- The Na+K+ ATPase moves Na+
out of the epithelial cells lining the intestine and into the
- The low concentration of Na+ inside the cell and
the high concentration of Na+ inside the
lumen of the intestine provide a diving force for the net movement
of Na+ inside the cell.
- The cotransporters in the membrane of the epithelial cell
facing the intestine allow Na+ to enter only when
accompanied by either glucose or one of the amino acids (each
have their own set of cotransporters).
- Thus, using ATP as an energy source to release Na+ inside
the cell results in the transport of glucose from the intestine
to the blood.
Membrane proteins must have an asynchronous distribution
on the cell membrane for the system to function. This is an example
of the membrane synthetic apparatus can determine where in a membrane
a protein should be localized. The Na+K+ ATPase
must be localized to
the membrane between the cell and our blood.
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