Question

Which of these statements about carrier-mediated facilitated diffusion is true? a. It uses cellular ATP. b. It is used for cellular uptake of blood glucose. c. It is a form of active transport. d. None of these are true.

Short answer

The correct answer is option "b. It is used for cellular uptake of blood glucose," as carrier-mediated facilitated diffusion is used for the cellular uptake of blood glucose through glucose transporter proteins (GLUT).

Step-by-step solution

Understand carrier-mediated facilitated diffusion

Carrier-mediated facilitated diffusion is a type of passive transport where substances, such as ions, water, and molecules, are moved across the cell membrane by means of specific transport proteins. Since it's a form of passive transport, it does not require energy input. Now let's analyze each statement.

Analyze statement a

"It uses cellular ATP." Carrier-mediated facilitated diffusion is a type of passive transport, which means it does not require energy. Therefore, it does not use cellular ATP for its function.

Analyze statement b

"It is used for cellular uptake of blood glucose." Carrier-mediated facilitated diffusion is indeed used for the cellular uptake of blood glucose. Glucose enters the cells through glucose transporter proteins (GLUT), which facilitate the diffusion of glucose across the cell membrane.

Analyze statement c

"It is a form of active transport." Carrier-mediated facilitated diffusion is not a form of active transport. It is actually a type of passive transport since it does not require energy to move substances across the cell membrane.

Analyze statement d

"None of these are true." Since statement b is true, this statement is false.

Final answer

Based on our analysis, the correct answer is option "b. It is used for cellular uptake of blood glucose." as carrier-mediated facilitated diffusion is used for the cellular uptake of blood glucose through glucose transporter proteins (GLUT).