Question

multiple choice question
which mechanism of solute transport is illustrated here?
primary active transport
passive diffusion
facilitated diffusion
group translocation

Explanation:

To determine the solute transport mechanism, we analyze each option:

• Primary active transport: Requires energy (e.g., ATP) to move solutes against a concentration gradient. The diagram does not show energy usage or movement against a gradient (solute moves from high to low concentration here).
• Passive diffusion: Occurs directly through the lipid bilayer, without a transport protein. The diagram shows a transport protein (the green channel), so this is not passive diffusion.
• Facilitated diffusion: Uses a transport protein (channel or carrier) to move solutes down their concentration gradient (high to low) without energy. The diagram shows solutes moving from a high - concentration side (left) to low - concentration (right) via a transport protein, matching facilitated diffusion.
• Group translocation: Chemically modifies the solute during transport (e.g., phosphorylation), which is not depicted here.

Answer:

facilitated diffusion