Question

which of the following is a key characteristic of active transport?
moves molecules down the concentration gradient
requires energy
transports small, uncharged molecules
does not require energy
question 8
1 pts
the sodium - potassium pump is an example of active transport because it:
moves molecules from high to low concentration
works only in plants
requires atp to move ions against the concentration gradient
uses a protein channel

Explanation:

Active transport is a process that moves substances against their concentration gradient. This requires energy (usually in the form of ATP). Passive transport (like simple diffusion) moves molecules down the concentration gradient and doesn't require energy. Small, uncharged molecules can be transported by passive processes (e.g., simple diffusion). The sodium - potassium pump moves \(Na^{+}\) and \(K^{+}\) against their concentration gradients and uses ATP for this purpose.

Answer:

For the first question: requires energy.
For the second question: requires ATP to move ions against the concentration gradient.