A friend receives the results of a urine test and finds that dissolved nutrients, such as amino acids and glucose, are present in his urine. You deduce that part of his kidney is not functioning properly. Which part is most likely malfunctioning?

Proximal tubules.

Explanation:

The proximal tubules make up a significant portion of the kidneys and they are also the site of active solute secretion, hormone production, and many of the metabolic functions of the kidney. This segment of the nephron in kidney has two main functions: absortion and secretion. A hundread percent of organic solutes, such as glucose and amino acids are reabsorbed, that's why they should not be present in his urine.

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.