Question

Which molecules need facilitated diffusion to move across the plasma membrane?

water
glucose
oxygen
carbon dioxide
amino acids

Answer 1

Glucose and amino acids need facilitated diffusion to move across the plasma membrane.

Facilitated diffusion is the movement of selective molecules across the cell or plasma membrane through the protein channels. The ions or molecules that move across the biological membrane by the help of specific integral trans-membrane proteins.

Glucose being a six carbon large molecule cannot be transported by the passive diffusion so it moves down the concentration gradient by facilitated diffusion. At the membrane, the carrier protein binds to glucose and alters its shape and then transports it from one side of the membrane to other.

The amino acids are also large molecules also get transported by the carrier trans-membrane proteins like permeases by altering their shape or conformation.

Answer 2

Glucose and amino acids are the molecules among the choices given in the question that need facilitated diffusion to move across the plasma membrane. The correct options among the options given in the question are the second option and the fifth option. I hope the answer has helped you.