So this is the function of our proximal convoluted tubule. So we conclude that what is reabsorbed back into our bloodstream from our filtrate are sodium ions, as well as potassium and chloride ions, water, glucose and amino acids. Now, why do we want to reabsorb these in the first place? Well, because our body does not want to waste things like amino acids and glucose, because we need that to build important things. We need glucose for ATP. We need amino acids to build our proteins.