A-Level Biology - Active Transport - Steps in How it Works | Bulk Transport (2027/28 exams)

Introduction to Active Transport00:00:07

Active transport is the process of moving particles against their concentration gradient, from an area of lower concentration to an area of higher concentration. Unlike diffusion, this process requires metabolic energy in the form of ATP.

Factors Affecting Active Transport Rate00:01:21

The rate of active transport is influenced by three main factors: the rate of respiration (providing ATP), the number of carrier proteins available, and temperature. Excessive heat can denature proteins, which ultimately decreases the transport rate.

Steps of Ion Transport00:02:15

The transport of ions involves six stages: binding of the ion to a carrier protein, ATP hydrolysis, the release of energy causing a shape change in the protein, transport across the membrane, release of the ion, and the protein returning to its original state.

Bulk Transport Mechanisms00:03:23

Bulk transport handles large substances or large quantities of molecules at once. This includes endocytosis (engulfing material into the cell via vesicles, including phagocytosis and pinocytosis) and exocytosis (fusing vesicles with the cell membrane to expel materials).