Definition: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Input: Question: Which process is not related to a proton gradient ?: 
 Options:  <1> Oxidative phosphorylation <2> Synthesis of NADPH. <3> Glucolysis <4> Heat production <5> Active transport.
