Question

Which method of transport in plasma membrane does not require carrier molecules?

• A. Simple diffusion
• B. Facilitated diffusion
• C. Active transport
• D. Na${}^{+}$- K${}^{+}$ pump mechanism

Answer 1

The correct option is A Simple diffusion

In passive transport, no energy is spent. Passive transport occurs through diffusion and osmosis. Simple diffusion is movement of particles from the region of their high concentration to the region of their lower concentration. Electrochemical potential operates in case of charged particles like ions. Facilitated diffusion occurs with the help of special facilitator proteins or permeases. Active transport requires special carriers and gated channels. Sodium potassium exchange pump operates across many animal membranes. The pump is operated by special proteins. For every ATP hydrolyzed, three sodium ions are passed out while two potassium ions are pumped in.