Human Digestive System

Pepsin is produced as the inactive zymogen pepsinogen by the zymogen (chief) cells of the stomach lining.

Pepsinogen is an inactive proenzyme. It is converted into the active enzyme pepsin by the acidic environment created by hydrochloric acid (HCl) in the stomach.

Rennin is the enzyme responsible for the coagulation of milk protein, specifically acting on caseinogen to form casein.

Pepsin is a digestive protease that is secreted and functions specifically within the stomach.

Pepsin is the enzyme secreted by the stomach wall that acts on proteins, such as casein, to begin the digestive process.

Gastric juice contains hydrochloric acid, giving it a very low pH (highly acidic) compared to saliva, bile, or pancreatic juice, which are neutral or alkaline.

HCl activates the zymogen pepsinogen into pepsin. Similarly, enterokinase (an intestinal enzyme) activates the pancreatic zymogen trypsinogen into trypsin.

Ptyalin (salivary amylase) functions in a neutral pH and is inactivated by the acidic environment of the stomach, whereas pepsin requires this acidic environment to be activated.

Pepsin is the primary gastric enzyme that hydrolyzes proteins into smaller peptide fragments.

Gastrin is a hormone secreted by G-cells in the stomach that stimulates the parietal cells to secrete gastric acid and promotes gastric juice secretion.

Pepsin is the primary enzyme responsible for the digestion of proteins in the stomach.

Peptic cells, also known as chief cells or zymogen cells, are responsible for secreting pepsinogen into the stomach lumen.

Rennin is a proteolytic enzyme specifically found in the gastric juice of young mammals, which is essential for the coagulation of milk protein (casein). Other enzymes like amylase or invertase are involved in carbohydrate digestion.

Parietal cells (also known as oxyntic cells) in the gastric glands secrete hydrochloric acid and intrinsic factor. Intrinsic factor is a glycoprotein necessary for the absorption of vitamin B12 in the small intestine.