Protein, Peptides, Amino Acids: Hydrolysis, Digestion, Absorption

Protein hydrolysis, digestion, and absorption are essential processes for your body to utilize protein as a source of amino acids, which are building blocks for many important molecules in your body.

Protein hydrolysis refers to the breakdown of proteins into smaller peptides and amino acids by adding water molecules. This process starts in your stomach, where the acidic environment and the enzyme pepsin begin breaking down proteins into smaller polypeptides.

Next, protein digestion continues in your small intestine, where pancreatic enzymes such as trypsin and chymotrypsin further break down polypeptides into smaller peptides and individual amino acids. These amino acids are then absorbed into the bloodstream through the walls of the small intestine.

These amino acids are used by the cells to synthesize various required proteins for the body or to synthesize some non-essential amino acids. Excess amino acids are deaminated in the liver and converted to glucose. This glucose enters the bloodstream to become an energy source for the cells or to synthesize glycogen and fat.

The traditional theory believed that protein has to be broken down into amino acids before it is absorbed by body. However, recent studies have shown that some oligopeptides can also be absorbed directly into the small intestine. These oligopeptides enter the body and are broken down by intracellular peptidases. They also have specific biological activities. The oligopeptides produced from collagen stimulate the body to produce more collagen.

Frequently Asked Questions

What are the essential amino acids for humans?

There are 8 amino acids that cannot be synthesized by human cells and must be consumed from diet. They are called essential amino acids: isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The liver function of infants is not fully developed and they cannot synthesize Histidine.

What are the risks of eating a lot of protein?

Protein has to be broken down into amino acids in order to be used by humans. Eating a lot of protein can lead to an excess of amino acids. They need to be converted to glucose by removing amino groups in the liver. This process produces toxic ammonia. If the amount of ammonia exceeds the liver's detoxification function, it will damage the nervous system.