Multiple Choice
How does active transport differ from passive transport across a cell membrane?
118
views
6. The Membrane
Passive vs. Active Transport
Multiple Choice
Which of the following molecules is most likely to passively diffuse across the plasma membrane?
A
ATP
B
O\(_2\) (oxygen gas)
C
Glucose
D
Na\(^+\) (sodium ion)
Verified step by step guidance1
Understand the concept of passive diffusion: Passive diffusion is the movement of molecules across the plasma membrane without the use of energy, driven by a concentration gradient. Molecules that are small, nonpolar, and uncharged are more likely to diffuse passively.
Analyze the properties of each molecule: ATP is a large, charged molecule; glucose is a polar molecule; Na\(^+\) is a charged ion; and O\(_2\) is a small, nonpolar molecule.
Recall that the plasma membrane is composed of a phospholipid bilayer: The hydrophobic (nonpolar) interior of the bilayer allows nonpolar molecules to pass through easily, while polar or charged molecules face resistance.
Determine which molecule fits the criteria for passive diffusion: O\(_2\) is small and nonpolar, making it the most likely candidate to diffuse passively across the plasma membrane.
Conclude that O\(_2\) is the correct answer because its properties align with the requirements for passive diffusion through the hydrophobic core of the plasma membrane.
Related Videos
Related Practice
