What are the carrier molecules used in active transport?

Question

What are the carrier molecules used in active transport?

Answer 1

Na+ or k+ pump

Answer 2

The carrier molecules are proteins embedded in the cell membrane.

Answer 3

They are transmembrane proteins.

Answer 4

Active transport requires ATP to move molecules against a concentration gradient.. Carrier molecules allows items like ions  (Na, K) to pass through the membrane since polar/hydrophilic things can't usually pass thru plasma membranes due to the hydrophobic/nonpolar tails of the lipid bilayer