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The movement of substances against their concentration gradient across a membrane, using energy released by respiration.

The movement of substances from a more dilute solution to a more concentrated solution, against the concentration gradient, using energy released by respiration.

Active transport moves a substance from a more dilute solution, where its concentration is lower, to a more concentrated solution, where its concentration is higher. This is movement against the concentration gradient.

The movement of substances against a concentration gradient using energy released by respiration.

For a definition of active transport, include all three ideas: movement from lower to higher concentration, against the concentration gradient, and a requirement for energy from respiration.

Do not say that active transport is a type of diffusion. Diffusion is passive and moves substances down a concentration gradient; active transport requires energy and moves substances against it.

In comparisons, state that osmosis concerns only water and requires a partially permeable membrane. Diffusion and active transport can move other substances.

The movement of substances against their concentration gradient, from lower to higher concentration, using energy released by respiration.

A difference in concentration between two regions is called a concentration gradient. This gradient determines the direction of diffusion and osmosis, while active transport allows cells to move substances in the opposite direction.

The movement of particles against their concentration gradient using energy.

Movement of a substance against its concentration gradient using energy released by respiration.

Three important processes move substances across it—diffusion, osmosis and active transport. Their crucial differences are the substance being moved, the direction of movement and whether cellular energy is required.

The movement of particles across a cell membrane against their concentration gradient, using energy released by respiration.

The movement of substances across a cell membrane from a lower to a higher concentration, using energy from ATP.

Moving it from lower to higher concentration is active transport. Proteins in the cell membrane carry the substance across, using energy supplied by ATP. Unlike diffusion and osmosis, active transport is not driven by movement down a concentration gradient.

The movement of a substance across a cell membrane from a lower concentration to a higher concentration, using energy from ATP.

The movement of substances across a cell membrane against their concentration gradient, using energy.

The movement of substances across a cell membrane using energy from ATP.

Active transport

Definition

How each exam board covers it

AQA GCSE Biology · 8461

Exam tips

Revise Biology with GradeGen

Edexcel GCSE Biology · 1BI0

OCR GCSE Biology A · J247

OCR GCSE Biology B · J257