Gastric juice is made up of substances secreted from parietal cells, chief cells

Question

Gastric juice is made up of substances secreted from parietal cells, chief cells, and mucous-secreting cells. The cells secrete HCl, proteolytic enzyme zymogens, mucin, and intrinsic factor. The pH of gastric juice is acidic, between 1-3. If the pH of gastric juice is 1.8, what is the amount of energy (AG) required for the transport of hydrogen ions from a cell (internaí pH of 7.4) into the stomach lumen? Assume that the potential difference across the membrane separating the cell and the interior of the stomach is -60.0 mV (inside of cells negative relative to the lumen of the stomach). Assume that the temperature is 37 . The Faraday constant is 96.5 kJ-V1 mol-1 and the gas constant is 8.314x10-3 kJ mor1. K-1. Express your answer in kJ/mol. Number kJ/ mol

Explanation / Answer

pH inside cell = 7.4

[H+ ] inside cell = 3.98×10^-8M

pH outside cell = 1.8

[H+] = 0.0158M

G= G° + RTlnK

from nernst equation

-0.060V = E° - (0.0592/n)log([H+]out/[H+]in)

E°=0.271V

G°= -nFE°

G° = -(1×96485C/mol× 0.271V)

= -26.14kJ/mol

G= G° + RTlnQ

= -26.14kJ/mol + (2.303×8.314(J/mol K)×log(0.0158M)/3.98×10^-8M)

=-26.14kJ/mol +33.23kJ/mol

= + 7.09kJ/mol

Related Questions

Navigate

• Browse (All)
• Browse G
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.