AP BIOLOGY

Detailed explanation-1: -Most of the solute reabsorbed in the proximal tubule is in the form of sodium bicarbonate and sodium chloride, and about 70% of the sodium reabsorption occurs here. Sodium reabsorption is tightly coupled to passive water reabsorption, meaning when sodium moves, water follows.

Detailed explanation-2: -Tubular reabsorption is the process by which solutes and water are removed from the tubular fluid and transported into the blood.

Detailed explanation-3: -Most of the glucose entering the tubular system is reabsorbed along the nephron segments, primarily in the proximal tubule, such that urine is almost free of glucose.

Detailed explanation-4: -Tubular reabsorption is the second major step in urine formation. Most of the reabsorption of solutes necessary for normal body function, such as amino acids, glucose, and salts, takes place in the proximal part of the tubule.

Detailed explanation-5: -About 67 percent of the water, Na+, and K+ entering the nephron is reabsorbed in the PCT and returned to the circulation. Almost 100 percent of glucose, amino acids, and other organic substances such as vitamins are normally recovered here.