<prompt> Answer this question truthfullyWhat is the process that occurs in the proximal tubule of the kidney when NH4 is generated, and what is the outcome of this process?  <response>: <reason> What happens in the proximal tubule of the kidney when NH4 is generated, and what is the outcome of this process? For each NH4 generated, one new HCO3- is synthesized and reabsorbed. 