Question

Which answer best identifies the difference between the two types of cellular transport? (B.4B) Question 3 options: Active transport uses ATP to move molecules against the concentration gradient. Facilitated diffusion uses ATP to move molecules down the concentration gradient. Diffusion move molecules through the cell membrane from an area of low to high concentration. Active transport uses ATP to move molecules against the concentration gradient. Active transport uses ATP to move molecules against the concentration gradient. Facilitated diffusion does not need ATP, but uses protein channels to move molecules down the concentration gradient. Facilitated diffusion does not need ATP, but uses protein channels to move molecules down the concentration gradient. Active transport uses ATP to move molecules down the concentration gradient.

Answer 1

• Active transport uses ATP to move molecules against the concentration gradient.

• Facilitated diffusion does not need ATP, but uses protein channels to move molecules down the concentration gradient

Step-by-step explanation:

Transmembrane proteins, among others, are the channel proteins and the carrier proteins, and they are in charge of substances transport into or out of the cell.

• Channel proteins are involved in passive transport, and facilitated diffusion is a kind of passive transport. Facilitated diffusion transport hydrophilic molecules that can not freely move through the membrane. Channel proteins carry them from one side to the other of the membrane, following the electrochemical gradient, so they do not need energy to carry in or out substances. Uncharged molecules´ movement depends on concentration gradients, while ions´ movement depends on an electrochemical gradient.

• Carrier proteins are involved in active transport. Active transport acts against the electrochemical gradient, so it does need the energy to transport substances. It carries molecules from a low concentration side to a high concentration side. The used energy comes from ATP (Na-K bomb) or the membrane´s electric potential.