$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \text{energy}$$

Question 1

Which of the following best describes primary active transport across the cell membrane?

Accepted Answer

It uses a pump protein and requires ATP to move molecules against their concentration gradient.

Question 2

The Na⁺/K⁺ pump is an example of which type of membrane transport?

Accepted Answer

Primary active transport

Question 3

During the operation of the Na⁺/K⁺ pump, what is the net movement of ions per ATP hydrolyzed?

Accepted Answer

3 Na⁺ out, 2 K⁺ in

Question 4

Which equation correctly represents the hydrolysis of ATP during active transport?

Accepted Answer

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} ightarrow \mathrm{ADP} + \mathrm{P}_i + 	ext{energy}$$

Question 5

Which of the following is TRUE about osmosis in cells?

Accepted Answer

Osmosis is always passive and driven by the water gradient, which is opposite to the solute concentration gradient.

Question 6

A patient is given a solution with a high concentration of sodium and glucose. What will happen to water movement across their intestinal cells?

Accepted Answer

Water will be osmotically pulled from the lumen into the interstitial fluid.

Question 7

Which of the following best explains secondary active transport?

Accepted Answer

It uses the energy stored in the electrochemical gradient created by primary active transport.

Question 8

Which of the following is a feature of mediated transport but NOT simple diffusion?

Accepted Answer

Saturation at high substrate concentrations

Question 9

Given the following concentrations from Table 4.1, which solute is most abundant in intracellular fluid compared to extracellular fluid?

Accepted Answer

K⁺

Question 10

Which of the following is NOT a property of carrier-mediated transport?

Accepted Answer

Always moves molecules down their concentration gradient

Question 11

Which type of chemical messenger is released by a cell and acts on nearby cells to produce a local effect?

Accepted Answer

Paracrine

Question 12

Which of the following is an example of a neurohormone?

Accepted Answer

Antidiuretic hormone (ADH)

Question 13

A cell releases interleukin-6 and responds to it itself. This is an example of which type of signaling?

Accepted Answer

Autocrine

Question 14

Which of the following statements about neurotransmitters is CORRECT?

Accepted Answer

They are released into the extracellular fluid at synaptic terminals.

Question 15

Which process is responsible for the movement of oxygen and carbon dioxide across the cell membrane?

Accepted Answer

Simple diffusion

Question 16

Which of the following is TRUE regarding the direction of water movement during osmosis?

Accepted Answer

Water moves toward higher solute concentration to dilute it.

Question 17

Which of the following is a distinguishing feature of primary active transport compared to secondary active transport?

Accepted Answer

It directly uses ATP to move molecules against their gradient.

Question 18

A patient with a genetic defect in the Na⁺/K⁺ pump would most likely experience which of the following?

Accepted Answer

Impaired maintenance of membrane potential

Question 19

Which of the following best describes the role of chemical messengers in intercellular communication?

Accepted Answer

They bind to receptors on target cells to trigger a response.

Question 20

Which of the following is TRUE about the sodium-linked glucose transport mechanism in intestinal cells?

Accepted Answer

It uses the energy from the Na⁺ gradient established by the Na⁺/K⁺ pump to actively transport glucose.

Cell Membrane Transport and Chemical Messengers: Study Notes lec 1

Study Guide - Practice Questions