Chief cells in the stomach secrete pepsinogen... what's the purpose of pepsinogen?

Question

I know that pepsinogen, in its active form is pepsin, breaks down proteins into peptide. But then doesn't pepsin digest the proteins of the stomach along with the food? So doesn't that mean that it will digest the proteins in the chief cells that produce it???

So if pepsinogen is the inactive form of pepsin, then it cannot digest proteins. So what is its function then?

I'm sorry if this is a little bit confusing.

Answer 1

see pepsinogen is secreted by the chief cells in the stomach and then in the stomach it is converted to pepsin. the chief cells secret it as pepsinogen so that the linings of your stomach wont get burnt by the low pH of pepsin. and the chief cells are located in the gastric pits of the stomach, they secret the pepsinogen into the lumen of your stomach so they arent mixed with the food themselves.

hope it helps

Answer 2

Pespinogen is inactive.  It is converted to pepsin after it is secreted so it will not damage the inside of the cell.

Answer 3

I think you answered your own question without realizing it!  Yes, pepsin would digest the proteins of the stomach, so the stomach is heavily lined with a layer of mucous (primarily made of carbohydrates, which are digested mostly in the mouth and intestine so is not as at risk of digestion in the stomach).  This mucous lining protects the stomach from all of that dangerous stuff going on inside, so that it doesn't digest itself or get degraded.  This is why pepsin has an intermediate form pepsinogen.  Like you said, pepsin would digest that which created it, so it is released in a safe form (pepsinogen).  Once in the stomach, the pepsinogen is activated by the hydrochloric acid, becoming pepsin.

Ironically, pepsin itself is a protein and it doesn't break itself down (although once it is formed, it continues to cleave pepsinogen to form more pepsin).