<prompt> Secondary active transport true is -Occurs only in same directionOccurs only in opposite directionUses ATP moleculeNo carrier required  <response>: Ans. is c i.e., Uses ATP molecule Active transporto As the name suggests active transport is active pumping of drug molecules through a membrane against concentration gradient by a molecular pump carrier mediated, which requires energy to function.o So, active transport has following characteristics:Movement is against concentration gradientA molecular pump carrier protein is required.Energy is requiredo On the basis of energy utilization, active transport is divided to:Primary- Direct active transporty Transporter carrier protein binds ATP directly and energy is obtained directly by the hydrolysis of ATP. These transporters carrier protein belong to the superfamily of ATP binding cassettee ABC transporters whose intracellular loops have ATPa.se activity.Examples are NaK ATPase. H-K ATPase, Ca2 ATPaseSecondary Indirect active transportThe energy to pump one solute is derived from the downhill movement of another solute, i.e. In secondary active transport, molecules are moved through a membrane as a result of the diffusion of other substance.When both molecules move in the same direction it is called svmport cotransport, e.g. Na -glucose transporter in the intestine. Na jodide transporter in thvroid-When molecules move in opposite directions, it is termed as antiport exchange transport e.g. Na-Ca2 exchanger in myocardium 