Question

Facilitated diffusion is an important method for cells in obtaining necessary molecules and removing other ones. Requirements for facilitated diffusion include which of the following?

A.The carrier molecule must be specific to the molecule that is transported. The direction of movement is always with the concentration gradient, never against the gradient.
B.The carrier molecule is nonspecific to the molecule that is transported. The direction of movement is always with the concentration gradient, never against the gradient.
C.The carrier molecule is nonspecific to the molecule that is transported. The direction of movement is always against the concentration gradient, never with the gradient.
D.The carrier molecule must be specific to the molecule that is transported and an ATP molecule must be attached to the specific carrier. The direction of movement is always against the concentration gradient, never with the gradient.

Answer 1

The correct answer is option A.The carrier molecule must be specific to the molecule that is transported. The direction of movement is always with the concentration gradient, never against the gradient.

Step-by-step explanation:

Facilitated diffusion is a process in which molecules move down their concentration gradient with the help of carrier proteins in the cell membrane. It is a type of passive transport that does not require energy.

A requirement for facilitated diffusion is that the carrier molecule must be specific to the molecule that is transported. This means that each carrier protein can only transport a specific molecule or group of molecules. For example, glucose transporters are carrier proteins that specifically transport glucose molecules.

The direction of movement in facilitated diffusion is always with the concentration gradient, never against it. This means that molecules are moving from an area of higher concentration to an area of lower concentration.