What is the function of pepsinogen in protein digestion?

Pepsinogen plays a crucial role in protein digestion as it is an inactive precursor of the enzyme pepsin. Upon exposure to stomach acid, particularly hydrochloric acid, pepsinogen is activated to pepsin, which is the enzyme responsible for hydrolyzing peptide bonds in proteins. This hydrolysis process breaks down the complex protein molecules into smaller peptides, making them easier for the body to further digest and absorb.

The activation of pepsinogen to pepsin highlights its specific function in the digestive process, as it is pivotal for initiating protein digestion in the acidic environment of the stomach. This is essential for the subsequent phases of digestion that occur in the small intestine, where proteins continue to be broken down into amino acids.

While other options involve important digestive processes, they do not pertain specifically to the role of pepsinogen. For instance, denaturing proteins is primarily the function of stomach acid rather than pepsinogen itself. Balancing pH in the stomach is also not related to pepsinogen, as this involves the function of other gastric secretions. Additionally, stimulating digestion of lipids does not involve pepsinogen, as lipid digestion is primarily facilitated by lipases rather than proteases like