Question

question 23
which molecules are most likely to require facilitated diffusion to cross the cell membrane?
a dna and large proteins needing the surface
b small nonpolar molecules like oxygen
c large or charged molecules like receptors in rna
d water vapor only

Explanation:

Facilitated diffusion is a type of passive transport that requires a protein channel or carrier. Large or charged molecules (like ions) cannot pass through the non - polar lipid bilayer of the cell membrane easily. Small non - polar molecules (like oxygen) can pass through by simple diffusion. DNA is not transported across the cell membrane in the way described in the options. Water can pass through the membrane by simple diffusion (osmosis) in some cases, but in many cells, it also uses aquaporins (facilitated diffusion). However, the question is about which molecules are "most likely" to require facilitated diffusion. Large or charged molecules (such as ions, amino acids, etc.) are the ones that typically and most clearly require facilitated diffusion as they cannot cross the hydrophobic core of the membrane easily.

Answer:

b. Large or charged molecules like ions