Oxyntic glands also contain Main cells that secrete the zymogen pepsinogen. Pepsinogen would be the precursor on the proteolytic enzyme pepsin and has to be activated to pepsin from the acidic pH of the belly (under 3.5) or from autoactivation by pepsin by itself. Pepsin then acts on The inner peptide bonds of proteins with the optimum pH of 2 to t… Read More