Which of the following is a difference between primary and secondary active transport?
In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated.
In primary active transport, energy comes directly from the hydrolysis of ATP and the subsequent phosphorylation of primary active transporter. In secondary active transport, the solute ( usually Na+) concentration gradient produced by primary active transport provides kinetic energy to move other solutes, such as ions and glucose, against their concentration gradient. For example, glucose can be transported against its concentration gradient through a Na+ glucose symporter as Na+ moves down its concentration gradient ( a gradient produced by the Na+K+ pump).