Secondary active transport true is -
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 Na+K+ ATPase. H+-K+ ATPase, Ca+2 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+-Ca+2 exchanger in myocardium
Occurs only in same direction
Occurs only in opposite direction
Uses ATP molecule
No carrier required
Transport Across Cell Membrane