Question

Acidification of urine occurs in
(A) Proximal tubule
(B) Distal tubule
(C) Loop of Henle
(D) None

Answer 1

Hint: Excretion is the removal of all the metabolic waste in the body. Kidney is the major excretory organ which eliminates the liquid waste in the form of urine. The kidney is made up of millions of small units called nephrons. The excretion takes place in these small levels of the kidney.

Complete answer:
The parts of the nephrons are glomerulus, proximal convoluted tubule, loop of Henle, distal convoluted tubule and the collecting duct. In the kidney, there occurs the purification of the blood and the elimination of the excess minerals, substance etc. The kidney also plays a vital role in the acid base balance of the body. This is done by two steps as H+ secretion in the urine and the bicarbonate ions reabsorption.
The H+ ions secretion mainly happens in the proximal convoluted tubule and this causes urine acidification. This also occurs in the collecting duct of the nephron. This secretion of H+ is possible by exchanging the sodium ions from the urine to the blood. This excretion of the H+ ions in the urine causes the urine acidic. The distal convoluted tubule is very less able to produce the H+ ions.

Hence the correct answer is OPTION(A)

Note: The hormones aldosterone secreted by the cortex portion of the adrenal gland that is located above the kidney. It stimulates the part of the nephron to absorb more and more water and the sodium from the urine to the blood. And so for this exchange of Na, H+ ions must be released in urine.