Substance X is a mostly polar molecule and Substance Y is a mostly non-polar molecule of a similar size.Which will diffuse from the extracellular fluid to the intracellular fluid faster if they are in equal concentrations outside and inside the cell?
A)Substance X will diffuse faster.
B)Substance Y will diffuse faster.
C)Substance X and Substance Y will diffuse at the same rate,as they are of equal size and concentration.

Question

Quizplus · Accepted Answer

Non-polar molecules, such as Substance Y, diffuse faster through the hydrophobic interior of the cell membrane compared to polar molecules, such as Substance X, which have to pass through the hydrophilic exterior and interior of the membrane. Therefore, Substance Y will diffuse faster from extracellular to intracellular fluid.

Substance X Is a Mostly Polar Molecule and Substance Y