1. Which of the following are the constituents of gastric juice?
   a. Water, trypsin and HCl
   b. HCl, pepsin and trypsin
   c. Water, pepsin and HCl
   d. Amylase, water and HCl

Gastric juice is a variable mixture ofwater, hydrochloric acid, electrolytes (sodium, potassium, calcium, phosphate, sulfate, and bicarbonate), and organic substances (mucus, pepsins, and protein). This juice is highly acidic because of its hydrochloric acid content, and it is rich in enzymes.