Active transport uses energy from ATP to move a substance against its concentration gradient (from an area of lower concentration to an area of higher concentration).

Sometimes this is done using a protein pump in the membrane, using ATP directly to move the substance from one side to the other.

Sometimes a co-transporter protein uses the concentration gradient of substance A to move substance B against its concentration gradient. However, the concentration gradient of substance A must be maintained in order for this to continue, and this is done using a protein pump (which uses ATP), so the co-transporter still needs ATP indirectly.

Hope this video helps explain this concept. Please feel free to leave any questions/comments.

Other videos in the series "Transport Across Cell Membranes":
cell membranes: [ Ссылка ]
diffusion: [ Ссылка ]
osmosis: [ Ссылка ]

Resources to check your knowledge: [ Ссылка ]

свернуть