What is active transport?

Active transport is one of the two modes of transport of material in and out of a cell, the other being passive transport. A cell is unable to make all the molecules it needs and is also incapable of using all the molecules it produces. And hence transport of molecules across the membrane is needed. It can take place as either active or passive transport, the latter of which which means no energy is used for this passive transport. Or the transport can be active transport, in which energy has to be spent to move molecules from regions of low concentration to regions of high concentration. Active transport also utilizes specialized membrane proteins, known as transport proteins, that facilitate the process of molecule transport. Large molecules, such as amino acids and glucose, are transported by the active transport mode of cross-membrane transport.

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