Which of the following is an example of positive feedback in the lumen of the stomach? which of the following is an example of positive feedback in the lumen of the stomach? hydrochloric acid converts pepsinogen to pepsin. pepsin works best in the acidic environment produced by hydrochloric acid. pepsin digests molecules of pepsinogen, producing more pepsin. chief cells secrete pepsinogen, which is a precursor to pepsin.

Option (3).

Explanation:

The homeostasis of the body is maintained by the feed back loop system. Two main types of the feedback loop system of the body are positive feedback system and negative feedback system.

Positive feedback system may be defined as the feedback in which the final product increases the output of that product. Pepsinogen is an zymogen that helps in the activation of pepsin enzyme. This enzyme helps in the digestion of protein. The digestion of pepsinogen by pepsin result in the more production of pepsin.

Thus, the correct answer is option (3).

cellular respiration oxidizes food into energy in the form of atps.

glycolysis (6 c hexose) > 2x atps are used > 6c hexose biphosphate > 2 x 3c triphosphate >

2 x 3c pyruvate (2x nadh produced from nad) and (4x atp produced)

pyruvate actively pumped mitochondrial matrix.