Question

which of the following transport mechanisms requires atp hydrolysis to move a molecule against its concentration gradient?
a. passive diffusion
b. active transport
c. cotransport
d. secondary active transport

Explanation:

Passive diffusion is a passive process that doesn't require energy. Cotransport and secondary - active transport often rely on the energy from an electrochemical gradient established by primary active transport rather than direct ATP hydrolysis for the specific transport step in question. Active transport directly uses ATP hydrolysis to move molecules against their concentration gradient.

Answer:

B. Active transport