Which of the following require energy?: (A) Simple diffusion, (B) Facilitated diffusion, (C) Passive transport, (D) Active transport
Answer is D. Ans: d (Active transport) Ref:Ganong, 22nd ed, p. 32The transport mechanism which requires energy is active transport. The different types of transport mechanisms are given below.Types of transport* Passive transportSimple diffusionFacilitated diffusion* Active transportSimple diffusion - along the cone gradient.No carrier involved.No energy requiredFacilitated diffusion - along the cone gradientCarrier mediatedNo energy required, bi-directionalActive transport - against the cone gradientCarrier mediatedRequire energy, unidirectional