Which substance will not be transported into a cell by simple diffusion?

Question

Quizplus · Accepted Answer

Epinephrine (adrenaline) is a hormone and neurotransmitter that is not lipid-soluble enough to pass through the cell membrane by simple diffusion. Instead, it typically binds to receptors on the cell surface, initiating a signaling cascade. In contrast, substances like oxygen (O2) and carbon dioxide (CO2) are small and nonpolar, allowing them to diffuse directly through the lipid bilayer of the cell membrane. Steroid hormones such as estrogen and cortisone are lipid-soluble and can also pass through the cell membrane by simple diffusion.

Which Substance Will Not Be Transported into a Cell by Simple