Q: Which of the following best describes the function of the sodium-potassium pump (Na\textsuperscript{+}-K\textsuperscript{+} ATPase) in maintaining the resting membrane potential (RMP) of a neuron?

It pumps 3 Na\textsuperscript{+} ions out of the cell and 2 K\textsuperscript{+} ions into the cell for each ATP hydrolyzed.

Q: Which of the following equations correctly represents the net movement of ions by the sodium-potassium pump per ATP molecule hydrolyzed?

$$3\ \mathrm{Na}^+_{\text{in}} + 2\ \mathrm{K}^+_{\text{out}} + \mathrm{ATP} \rightarrow 3\ \mathrm{Na}^+_{\text{out}} + 2\ \mathrm{K}^+_{\text{in}} + \mathrm{ADP} + \mathrm{P}_i$$

Q: Which of the following best explains why the resting membrane potential (RMP) of most cells is close to $$-90\ \mathrm{mV}$$?

The membrane is more permeable to K\textsuperscript{+} than to Na\textsuperscript{+}, and K\textsuperscript{+} diffuses out of the cell.

Q: Which of the following scenarios best illustrates secondary active transport in the small intestine?

Glucose is transported into epithelial cells along with Na\textsuperscript{+} ions via a symporter, using the Na\textsuperscript{+} gradient established by the Na\textsuperscript{+}-K\textsuperscript{+} pump.

Q: A cell is exposed to a toxin that inhibits ATP production. Which of the following transport processes would be most immediately affected?

Primary active transport of Na\textsuperscript{+} and K\textsuperscript{+}

Question 1

Which of the following best describes the function of the sodium-potassium pump (Na	extsuperscript{+}-K	extsuperscript{+} ATPase) in maintaining the resting membrane potential (RMP) of a neuron?

Accepted Answer

It pumps 3 Na	extsuperscript{+} ions out of the cell and 2 K	extsuperscript{+} ions into the cell for each ATP hydrolyzed.

Question 2

A cell is placed in a solution containing a high concentration of glucose. Which membrane transport process would most likely be used to move glucose into the cell against its concentration gradient?

Accepted Answer

Secondary active transport using a symporter

Question 3

Which of the following equations correctly represents the net movement of ions by the sodium-potassium pump per ATP molecule hydrolyzed?

Accepted Answer

$$3\ \mathrm{Na}^+_{	ext{in}} + 2\ \mathrm{K}^+_{	ext{out}} + \mathrm{ATP} ightarrow 3\ \mathrm{Na}^+_{	ext{out}} + 2\ \mathrm{K}^+_{	ext{in}} + \mathrm{ADP} + \mathrm{P}_i$$

Question 4

Which of the following best explains why the resting membrane potential (RMP) of most cells is close to $$-90\ \mathrm{mV}$$?

Accepted Answer

The membrane is more permeable to K	extsuperscript{+} than to Na	extsuperscript{+}, and K	extsuperscript{+} diffuses out of the cell.

Question 5

A patient is diagnosed with a genetic defect that impairs the function of clathrin-coated pits. Which cellular process would be most directly affected?

Accepted Answer

Receptor-mediated endocytosis

Question 6

Which of the following scenarios best illustrates secondary active transport in the small intestine?

Accepted Answer

Glucose is transported into epithelial cells along with Na	extsuperscript{+} ions via a symporter, using the Na	extsuperscript{+} gradient established by the Na	extsuperscript{+}-K	extsuperscript{+} pump.

Question 7

Which of the following best describes the difference between symporters and antiporters?

Accepted Answer

Symporters move two substances in the same direction, while antiporters move them in opposite directions.

Question 8

A white blood cell engulfs a bacterium by extending pseudopods around it and enclosing it in a vesicle. This process is best described as:

Accepted Answer

Phagocytosis

Question 9

Which of the following is a key difference between primary and secondary active transport?

Accepted Answer

Primary active transport uses energy from ATP hydrolysis directly, while secondary active transport uses the energy stored in ion gradients.

Question 10

A cell is exposed to a toxin that inhibits ATP production. Which of the following transport processes would be most immediately affected?

Accepted Answer

Primary active transport of Na	extsuperscript{+} and K	extsuperscript{+}

Question 11

Which of the following best describes the role of vesicular transport in neurotransmitter release at a synapse?

Accepted Answer

Neurotransmitters are released from the presynaptic neuron by exocytosis, which requires ATP.

Question 12

Which of the following statements about the resting membrane potential (RMP) is correct?

Accepted Answer

RMP is due to the selective permeability of the membrane to K	extsuperscript{+} ions and the activity of the Na	extsuperscript{+}-K	extsuperscript{+} pump.

Question 13

A cell needs to secrete a large amount of hormone into the bloodstream. Which process will it most likely use?

Accepted Answer

Exocytosis

Question 14

Which of the following best explains why the Na	extsuperscript{+}-K	extsuperscript{+} pump is considered an antiporter?

Accepted Answer

It moves Na	extsuperscript{+} and K	extsuperscript{+} in opposite directions across the membrane.

Question 15

Which of the following is a real-life example of receptor-mediated endocytosis?

Accepted Answer

A cell taking in low-density lipoprotein (LDL) cholesterol via specific membrane receptors

Question 16

A scientist observes that a cell is able to move large quantities of fluid and dissolved solutes into itself by forming small vesicles. Which process is being observed?

Accepted Answer

Pinocytosis

Question 17

Which of the following best describes the energy source for secondary active transport?

Accepted Answer

The movement of one solute down its concentration gradient, established by primary active transport

Question 18

A cell is exposed to a drug that blocks all carrier proteins in the plasma membrane. Which of the following processes would be most directly impaired?

Accepted Answer

Facilitated diffusion of glucose

Question 19

Which of the following best explains why the Na	extsuperscript{+}-K	extsuperscript{+} pump is essential for nerve and muscle function?

Accepted Answer

It maintains the chemical and electrical gradients necessary for action potentials.

Membrane Transport and Cellular Structures in Anatomy & Physiology

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