In the Proximal Tubule, Hydrogen Ions Are Transported into the Filtrate

question 94

Multiple Choice

In the proximal tubule, hydrogen ions are transported into the filtrate by

• A) Na⁺/H⁺countertransporters only.
• B) H⁺ primary active transporters only.
• C) H⁺/Cl ^- cotransporters only.
• D) both Na⁺/H⁺ countertransporters and H⁺ primary active transporters.
• E) both Na⁺/H⁺ countertransporters and H⁺/Cl ^-cotransporters.

---

Definitions:

Centromere

The region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division.

Chromatin

The complex of DNA and histone proteins that forms chromosomes within the nucleus of eukaryotic cells, regulating gene expression.

Membrane Potential

The voltage difference across a cell's membrane, crucial for the function of excitable cells like neurons and muscle cells.

Extracellular Glycocalyx

A complex carbohydrate-rich layer that coats the outer surface of cells, playing key roles in cell-cell interactions and protection.