In primary active transport, the energy is derived directly from the breakdown of ATP. In the secondary active transport, the energy is derived secondarily from energy that has been stored in the form of ionic concentration differences between the two sides of a membrane.

What happens in primary active transport?

Primary active transport, also called direct active transport, directly uses chemical energy (such as from adenosine triphosphate or ATP in case of cell membrane) to transport all species of solutes across a membrane against their concentration gradient.

What is an example of primary active transport?

An example of primary active transport using redox energy is the mitochondrial electron transport chain that uses the reduction energy of NADH to move protons across the inner mitochondrial membrane against their concentration gradient.