The movement of a chemical substance through a gradient of concentration or electrical potential in the direction opposite to normal diffusion, requiring the expenditure of energy: active transport across a cell membrane
{i} (Chemistry, Biochemistry) molecular movement, transport of ions or nutrients or other molecules across cell membranes from low to high concentrations that necessitates consumption of energy
The transport, requireing energy, of a molecule across a membrane against a concentration gradient
the movement of a substance into or out of a cell using energy, usually against to a concentration gradient
An energy expending mechanism by which a cell moves a chemical across the cell membrane from a point of lower concentration to a point of higher concentration, against the diffusion (concentration) gradient
transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient; requires an expenditure of energy
is the movement of a substance across a biological membrane with the help of energy input (ATP) and specific transport proteins
An energy-expending mechanism by which a cell moves a chemical across the cell membrane from a point of lower concentration to a point of higher concentration, against the diffusion gradient