Question 1

Which of the following best describes secondary active transport in cellular membranes?

Accepted Answer

It relies on the electrochemical gradient established by primary active transport to move molecules against their gradient.

Question 2

In the sodium-potassium pump, which equation best represents the energy source for primary active transport?

Accepted Answer

$$ \mathrm{ATP} \rightarrow \mathrm{ADP} + \mathrm{P_i} $$

Question 3

Which of the following is a real-life example of secondary active transport in human physiology?

Accepted Answer

Glucose absorption in the small intestine via the sodium-glucose symporter.

Question 4

What is the main difference between primary and secondary active transport?

Accepted Answer

Primary active transport uses ATP directly, while secondary active transport uses the gradient created by primary active transport.

Question 5

Which of the following statements about the sodium-potassium pump is correct?

Accepted Answer

It creates an electrochemical gradient by pumping sodium out and potassium in, using ATP.

Question 6

If the sodium-potassium pump is inhibited, what would be the most immediate effect on secondary active transport of glucose?

Accepted Answer

Glucose transport would decrease due to loss of the sodium gradient.

Question 7

Which equation best represents the coupling of sodium and glucose transport in secondary active transport?

Accepted Answer

$$ \mathrm{Na^+_{out}} + \mathrm{Glucose_{out}} \rightarrow \mathrm{Na^+_{in}} + \mathrm{Glucose_{in}} $$

Question 8

Which of the following is NOT a feature of secondary active transport?

Accepted Answer

It directly hydrolyzes ATP for energy.

Question 9

A patient is found to have a genetic defect in the sodium-glucose symporter. Which of the following symptoms would most likely result?

Accepted Answer

Reduced glucose absorption in the intestines.

Question 10

Which of the following best explains why primary active transport is necessary for secondary active transport to occur?

Accepted Answer

Primary active transport establishes the ion gradient that secondary active transport uses to move other molecules.

Question 11

Which of the following transporters is most likely to be involved in secondary active transport?

Accepted Answer

Symporter

Question 12

In a cell, the concentration of sodium is higher outside than inside. Which process is responsible for maintaining this gradient?

Accepted Answer

Primary active transport via the sodium-potassium pump

Question 13

Which of the following scenarios best illustrates the cooperative function of primary and secondary active transport?

Accepted Answer

The sodium-potassium pump uses ATP to create a sodium gradient, which is then used by the sodium-glucose symporter to import glucose against its gradient.

Question 14

Which of the following is a consequence of inhibiting primary active transport in a cell?

Accepted Answer

Secondary active transport processes would be impaired due to loss of ion gradients.

Question 15

Which of the following best describes the energy coupling in secondary active transport?

Accepted Answer

The movement of one ion down its gradient provides the energy to move another molecule against its gradient.

Secondary Active Membrane Transport: Mechanisms and Examples

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