Question

What is true about distal convoluted tubules?
A) Ammonia is excreted
B) Water reabsorption requires energy
C) $K^+$ reabsorption does not require energy
D) $Na^+$ reabsorption requires energy

Answer 1

The distal twisted tubule is the part of the nephron that lies rapidly downstream of the thick macula. The distal tangled tubule assumes a fundamental role of sodium, potassium and divalent cation homeostasis.

Complete answer:
The assimilation of particles, including sodium, chloride and calcium, is part of early DCT. The movement of these particles depends on the ability of the carrier of the Na+ or K+ ATPase on the basolateral surface. This discharges into the extracellular liquid sodium particles, and brings potassium particles into the phone. This channel reduces the intracellular sodium levels, creating an angle that favours the sodium development of the cell.

Conditional reabsorption of $Na^+$ and water occurs in the distal convoluted tubule (DCT). The filtrate can grow thinner as it passes through the distal tubule. The distal tubule is relatively impermeable but transfers salt actively into the fluid of the tissue. Hydrogen, potassium ions, and to maintain blood pH and sodium-potassium equilibrium, DCT can also reabsorb and selectively secrete. The reabsorption of $Na^+$ DCT requires energy and is an active operation.

Additional information:
The mechanism of maintaining salt and water equilibrium (osmotic balance) through membranes within the body is osmoregulation. The fluids are made of water, electrolytes, and nonelectrolytes inside and outside cells. An electrolyte is a compound that, when dissolved in water, dissociates into ions.

Hence, the correct answer is option D.

Note: The proximal convoluted tubule is the initial component of the renal tubule. As it is nearest to the starting point (the renal corpuscle) and twists due to twisting, it is called the proximal end (as opposed to the straight section of the tubule that forms the loop of Henle).