How does hydrochloric acid break down proteins?
HCL breaks down proteins in your stomach to prepare them for digestion and kills bacteria that enter your stomach. It converts the inactive enzyme pepsinogen into the active enzyme pepsin, which is responsible for digesting proteins in your stomach. HCL also helps digest other foods in your stomach.
This process is called denaturation and happens during cooking and exposure to acid. In addition to denaturing the three-dimensional structure of dietary protein, hydrochloric acid activates pepsinogen and converts it to the enzyme pepsin. Pepsin then begins to break the peptide bonds, forming smaller peptide chains.
- The small intestine is the part of the intestines where 90% of the digestion and absorption of food occurs, the other 10% taking place in the stomach and large intestine. The main function of the small intestine is absorption of nutrients and minerals from food. Digestion involves two distinct parts.
- The Rules of Protein Structure. The function of a protein is determined by its shape. The shape of a protein is determined by its primary structure (sequence of amino acids). The sequence of amino acids in a protein is determined by the sequence of nucleotides in the gene (DNA) encoding it.
- In the digestive tract pepsin effects only partial degradation of proteins into smaller units called peptides, which then either are absorbed from the intestine into the bloodstream or are broken down further by pancreatic enzymes.
Most proteins begin digestion in the stomach. Cells of the stomach secrete the inactive zymogen pepsinogen, which is an enzyme that is activated by HCl. In its active form, pepsinogen is called pepsin. Pepsin breaks the peptide bonds that link amino acids.
- Activation of pepsinogen starts when hydrocholoric acid (HCl), which is secreted by the parietal cells partially activates pepsinogen (pepsinogen* in figure). This partially active enzyme then cleaves the peptide from other pepsinogen molecules to form active pepsin.
- Enzyme - General Information
Enzyme Substrate Products Lipase Lipid Glycerol + Fatty Acid Enzyme Substrate Products Pepsin Protein Peptides + Amino Acids Trypsin Protein Peptides + Amino Acids
- Pepsinogen production is stimulated by the presence of gastrin in the blood. Hydrochloric acid (HCl) converts pepsinogen to pepsin which breaks down proteins to peptides. HCl maintains a pH in the stomach of approximately 2.0. It also dissolves food and kills microorganisms.
The primary role of hydrochloric acid is to sterilize the food you eat and to prevent harmful bacteria from entering the GI tract. HCL also triggers the release of enzymes such as pepsin which are essential for the digestion of protein.
- Proteins are digested in the stomach and small intestine. Protease enzymes break down proteins into amino acids. Digestion of proteins in the stomach is helped by stomach acid, which is strong hydrochloric acid.
- Stomach acid plays an essential role in the immune system by killing harmful bacteria and parasites that are ingested with food. Stomach acid activates the enzyme pepsin needed for protein digestion. Stomach acid signals to the pancreas produce digestive juices and enzymes to further break down food.
- Its job is to absorb most of the nutrients from what we eat and drink. Velvety tissue lines the small intestine, which is divided into the duodenum, jejunum, and ileum. The large intestine (colon or large bowel) is about 5 feet long and about 3 inches in diameter. The colon absorbs water from wastes, creating stool.
Updated: 3rd October 2018