A bacterial cell moves lactose molecules from a region of low concentration outside the cell to a region of high concentration inside the cell. Which statement below accurately describes this scenario?

An ecologist studying oceanic algae measures the diffusion rates of nitrate under varying external concentrations. The results show nitrate diffusion happens rapidly at low external concentrations but slows down as these increase. What does this imply?

Which of the following does not affect the ability of the molecule to move across a cell membrane?

What property of the cellular membrane allows the passage of some molecules and prevents the diffusion of other molecules?

Which of the following molecules can easily pass through the cellular membrane?