Symptoms of a urinary tract infection (UTI) are similar in men, women, and children. Early symptoms and signs are usually easy to recognize and primarily involve pain, discomfort, or burning when trying to urinate.
Protein digestion begins in the stomach with the action of an enzyme that we previously learned about called pepsin. Pepsin is the active protein-digesting enzyme of the stomach. When pepsin acts on the protein molecule, it breaks the bonds that hold the protein molecule together, called peptide bonds.
1 It is produced by the stomach cells called chief cells in its inactive form pepsinogen, which is a zymogen. 2  Pepsinogen is then activated by the stomach acid into its active form, pepsin. 3  Pepsin breaks down the protein in the food into smaller particles, such as peptide fragments and amino acids. Pepsin breaks down the protein in the food into smaller particles, such as peptide fragments and amino acids. 2  Protein digestion, therefore, first starts in the stomach, unlike carbohydrate and lipids, which start their digestion in the mouth.