Question

which transport mechanism uses atp - binding cassette transporters?

• passive diffusion
• primary active transport
• facilitated diffusion
• secondary active transport

Explanation:

• Passive diffusion: Does not require energy or transporters, so incorrect.
• Primary active transport: Uses ATP directly to move substances against concentration gradients. ATP - binding cassette transporters are a type of primary active transporters that use ATP hydrolysis for transport.
• Facilitated diffusion: Uses transporters but no ATP (relies on concentration gradient), so incorrect.
• Secondary active transport: Uses energy from ion gradients (not direct ATP hydrolysis), so incorrect.

Answer:

B. Primary active transport