Dear student,
Distal convoluted tubule forms the descending part of the renal tubule, situated just below the malpighian corpuscle. Its function is to absorb the selective nutrients like glucose back to the blood. The secretion of potassium and other foreign particles is due to the increased electronegativity of the fluid due to sodium reabsorption in order to maintain the net movement of sodium across the tubule.
Regards