The correct answer is active transport.
For this kind of transport the cell requires energy, usually in the form of ATP, to move a molecule against its concentration gradient.
There are two types of active transport:
Primary active transport which directly uses a source of chemical energy to move molecules. Example: sodium-potassium pump
Secondary active transport (cotransport), which uses an electrochemical gradient (generated by active transport)as an energy source to move molecules. Example: glucose symporter SGLT1
Answer;
-Active transport
Explanation;
-Active transport involves movement of substances against a concentration gradient. To move substances against a concentration or electrochemical gradient, a cell must use energy.
-Dissolved molecules move across a cell membrane from a lower to a higher concentration. In active transport, particles move against the concentration gradient and therefore require an input of energy from the cell.
-Additionally, active transport require carrier proteins (solute pumps). Protein carriers bind specifically and reversibly with substance being moved . Some carriers transport more than one substance. Antiporters transport one substance into cell while transporting a different substance out of cell, while symporters transport two different substances in the same direction.
