Active transport is a biological process by which cells move molecules or ions against their concentration gradient, from an area of lower concentration to an area of higher concentration, using energy from ATP. This process is essential for the proper functioning of cells and is involved in many physiological processes.
Definitions
Active transport is defined as the movement of molecules or ions across a cell membrane from an area of low concentration to an area of high concentration, requiring the use of energy. This process is carried out by membrane-bound proteins called transporters or pumps, which use ATP to move molecules against their concentration gradient.
Origin
The concept of active transport was first proposed by the German physiologist, Adolf Fick, in 1885. He suggested that cells could actively transport molecules across their membrane, against their concentration gradient, using energy from ATP. This idea was later supported by the work of other scientists, including Peter Mitchell, who won the Nobel Prize in Chemistry in 1978 for his work on the chemiosmotic theory of energy transduction.
Meaning in different dictionaries
According to the Oxford English Dictionary, active transport is defined as “the movement of molecules or ions across a cell membrane against a concentration gradient, requiring the expenditure of energy”. The Merriam-Webster Dictionary defines it as “the movement of ions or molecules across a cell membrane in the direction opposite to diffusion and requiring the expenditure of energy”.
Associations
Active transport is associated with many physiological processes, including the absorption of nutrients in the small intestine, the reabsorption of ions in the kidney, and the transport of neurotransmitters in the nervous system. It is also involved in the regulation of cell volume and the maintenance of ion gradients across cell membranes.
Synonyms
Synonyms of active transport include energy-dependent transport, uphill transport, and primary active transport.
Antonyms
Antonyms of active transport include passive transport, which is the movement of molecules or ions across a cell membrane from an area of high concentration to an area of low concentration, without the use of energy.
The same root words
The same root words as active transport include activity, active, and transport, which all relate to the movement of molecules or energy.
Example Sentences
- The absorption of glucose in the small intestine is an example of active transport.
- The sodium-potassium pump is a type of active transport that is involved in the regulation of cell volume.
- Active transport is essential for the proper functioning of cells and is involved in many physiological processes.