Active transport：練習題

What is the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration, using energy from respiration?

Active transport is essential for the survival of many cells. Which of the following best describes the movement of particles during this process and the requirement for its occurrence?

The table shows the concentration of certain ions in the vacuoles of an aquatic plant and in the surrounding pond water.

- Pond water: \( 1.2 \) units
- Cell vacuole: \( 45.0 \) units

Which statement correctly explains how the plant maintains this difference in concentration?

Which specialised plant cell is specifically adapted for the active transport of mineral ions from the soil?

A cell is treated with a chemical that prevents protein carriers in the cell membrane from functioning.

Which process will be most directly stopped by this chemical?

Explain why active transport requires energy.

A root hair cell is treated with a chemical that prevents the release of energy from respiration. Explain the effect this would have on the cell's ability to absorb mineral ions that are in lower concentration in the soil than in the cell sap.

Explain two key differences between active transport and facilitated diffusion with respect to particle movement across cell membranes.

Active transport is a vital process that allows cells to absorb necessary substances even when they are in low concentrations outside the cell.

(a) Define the term active transport with reference to the direction of particle movement and the concentration gradient.

(b) State the name of the cellular process that provides the energy needed for active transport.

(c) Name the specific structures located in the cell membrane that move molecules or ions during this process.

(d) State one example of a plant cell that uses active transport to take up mineral ions.

Active transport is a vital process for cells. Describe active transport, including the role of energy and protein carriers. Explain why this process is essential for the uptake of mineral ions by plant root hair cells, even when their concentration is much higher inside the cell than in the soil.