Question

Which of the following can passs directly across the plasma membrane?
Group of answer choices

small hydrophobic molecules

ions

charged particles

all of the above

Answers

GPT-4o mini
Among the options provided, the correct answer is:

**small hydrophobic molecules**

Small hydrophobic molecules can pass directly across the plasma membrane due to their ability to dissolve in the lipid bilayer.

In contrast, ions and charged particles typically cannot pass directly through the plasma membrane without the aid of transport proteins or channels, due to the hydrophilic nature of the membrane's surface. Therefore, they usually require specific transport mechanisms to cross the membrane.