Define the following terms:
$(1)$ Diffusion
$(2)$ Facilitated Diffusion

What is active transport?

$A-$ In an antiport,both molecules move in opposite directions.
$R -$ In symport,only one molecule crosses the membrane in the same direction.

Consider the following statements and choose the correct answer:
$I.$ Carrier proteins are needed by both facilitated diffusion and active transport and are sensitive to inhibitors that react with protein side chains.
$II.$ Different types of proteins present in the membrane play a major role in both active as well as passive transport.
$III.$ The carrier proteins needed by facilitated and active transport are specific.
$IV.$ There is no need of energy to pump molecules against a concentration gradient in active transport.
$V.$ Transport rate reaches a saturation point when all the active proteins are used.

Mention the peculiarities of facilitated diffusion.

This transport occurs along the concentration gradient.