What is similar between facilitated diffusion and primary/secondary active transport? In both forms of transport .

Membrane transport protein is invloved

Explanation:

Diffusion; It is the movement of molecules from an area of higher concentration to an area of lower concentration without the expend of energy. Only simple non polar molecules can pass through membrane by simple diffusion.

Facilitated Diffusion; It is the diffusion of certain molecules through transport channels that are usually made up of membrane glycoproteins such as GLUT4 are involved in glucose transport.

Primary Active transport; It is the movement of molecules from an area of lower concentration to an area of higher concentration on the expend of energy (ATP). Membrane protein transfer the molecule by consuming the energy. Such as sodium potassium ATPase pumps.

Secondary Active transport; It does not use direct source of energy and use the electrochemical gradient set by primary active transport to transport the molecules against the concentration gradient. For example if sodium gradient is high on one side of membrane it can be used for the the transport of other molecules by a shared carrier protein.