Q: Which of the following best describes the energy source used by the Na\textsuperscript{+}-glucose symporter in intestinal epithelial cells?

The Na\textsuperscript{+} gradient established by the Na\textsuperscript{+}/K\textsuperscript{+}-ATPase.

Q: What would be the most likely result of a mutation that inactivates the Na\textsuperscript{+}/K\textsuperscript{+}-ATPase in an intestinal epithelial cell?

Decreased Na\textsuperscript{+} gradient and reduced glucose absorption.

Q: Which of the following best explains why the Na\textsuperscript{+}-glucose symporter can move glucose against its concentration gradient?

It uses the energy stored in the Na\textsuperscript{+} electrochemical gradient.

Q: Which of the following is a direct consequence of inhibiting the Na\textsuperscript{+}/K\textsuperscript{+}-ATPase in intestinal epithelial cells?

Increased intracellular Na\textsuperscript{+} concentration.

Q: Which experiment would show a lower rate of glucose transport via the Na\textsuperscript{+}-glucose symporter: one with normal extracellular Na\textsuperscript{+} or one with reduced extracellular Na\textsuperscript{+}?

The experiment with reduced extracellular Na\textsuperscript{+}.

Question 1

Which of the following best describes the energy source used by the Na	extsuperscript{+}-glucose symporter in intestinal epithelial cells?

Accepted Answer

The Na	extsuperscript{+} gradient established by the Na	extsuperscript{+}/K	extsuperscript{+}-ATPase.

Question 2

What would be the most likely result of a mutation that inactivates the Na	extsuperscript{+}/K	extsuperscript{+}-ATPase in an intestinal epithelial cell?

Accepted Answer

Decreased Na	extsuperscript{+} gradient and reduced glucose absorption.

Question 3

Which of the following statements about the Na	extsuperscript{+}-glucose symporter is TRUE?

Accepted Answer

It is an example of secondary active transport.

Question 4

In the context of intestinal glucose absorption, what is the primary role of the GLUT2 transporter?

Accepted Answer

To facilitate glucose diffusion from the epithelial cell into the bloodstream.

Question 5

Which of the following best explains why the Na	extsuperscript{+}-glucose symporter can move glucose against its concentration gradient?

Accepted Answer

It uses the energy stored in the Na	extsuperscript{+} electrochemical gradient.

Question 6

If the extracellular Na	extsuperscript{+} concentration is decreased, what will happen to the rate of glucose uptake via the Na	extsuperscript{+}-glucose symporter?

Accepted Answer

It will decrease.

Question 7

Which of the following is a direct consequence of inhibiting the Na	extsuperscript{+}/K	extsuperscript{+}-ATPase in intestinal epithelial cells?

Accepted Answer

Increased intracellular Na	extsuperscript{+} concentration.

Question 8

Which of the following best describes the mechanism of secondary active transport?

Accepted Answer

Transport of one molecule is driven by the movement of another molecule down its gradient.

Question 9

A patient has a genetic defect in the Na	extsuperscript{+}-glucose symporter. Which of the following symptoms would you most likely expect?

Accepted Answer

Decreased glucose absorption in the intestine.

Question 10

Which experiment would show a lower rate of glucose transport via the Na	extsuperscript{+}-glucose symporter: one with normal extracellular Na	extsuperscript{+} or one with reduced extracellular Na	extsuperscript{+}?

Accepted Answer

The experiment with reduced extracellular Na	extsuperscript{+}.

Question 11

Which of the following is NOT a function of the Na	extsuperscript{+}/K	extsuperscript{+}-ATPase in epithelial cells?

Accepted Answer

Directly transporting glucose into the cell.

Question 12

Which of the following best describes the direction of Na	extsuperscript{+} and glucose movement by the Na	extsuperscript{+}-glucose symporter?

Accepted Answer

Both Na	extsuperscript{+} and glucose move into the cell.

Question 13

Which of the following is the best example of secondary active transport in the intestinal epithelium?

Accepted Answer

Na	extsuperscript{+}-glucose symporter.

Question 14

Which of the following would most likely occur if the GLUT2 transporter was nonfunctional in intestinal epithelial cells?

Accepted Answer

Glucose would accumulate inside the epithelial cell.

Glucose Active Symporter Model and Sodium-Glucose Transport in Epithelial Cells

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