Question

Under severe acidic conditions, the proximal tubules can convert ________ into bicarbonate.

1) glutamate
2) carbon monoxide
3) lysine
4) glutamine
5) glycine

Answer 1

The proximal tubules in the kidneys convert glutamine into bicarbonate under severe acidic conditions, aiding in maintaining the body's acid-base balance.

Step-by-step explanation:

Under severe acidic conditions, the proximal tubules can convert glutamine into bicarbonate. The amino acid glutamine can be deaminated by the kidney to assist in the buffering and excretion of acid. As NH2 from glutamine is converted into NH3 (ammonia) and pumped into the lumen of the PCT (Proximal Convoluted Tubule), Na+ and HCO3− (bicarbonate ions) are excreted into the interstitial fluid of the renal pyramid via a symport mechanism. This process results in a net loss of a hydrogen ion in the urine and a gain of bicarbonate in the blood, helping to maintain acid-base balance.