Chemistry of enzymes makes digestion easier

Food is considered as one of the essentials in day to day to human life or in fact animals and other living organisms also. However,

  Did anybody think about how food will be processed starting from mouth to stomach?

     What are the factors involving and responsible for the proper digestion?

Digestion

It is nothing but chemical breakdown of large food molecules into smaller molecules. Some of the food molecules include

• Proteins
• Lipids
• Carbohydrates
• Fatty acids (Fats)

In specific there is certain biochemicals called Enzymes play vital role in digestion. These are

• Salivary amylase
• Pancreatic amylase
• Maltase
• Pepsin
• Trypsin
• Peptidases
• Lipase

The most important enzymatic reaction in digestion of foodstuffs is hydrolysis - the breaking of a chemical bond by the addition of a water molecule.

Digestion process

Digestion process starts in mouth where salivary amylase starts its work by breaking larger molecules i.e, polysaccharides to smaller molecules i.e, disaccharides. The saliva present in mouth contains Bicarbonate ions acts as buffer which maintains pH of 6.5 to 7.5.

Second place of digestion is in stomach where Hydrochloric acid (HCl) plays major role in digestion. HCl maintains a pH in the stomach of 2.0. It also dissolves food and kills microorganisms.

Once food processed in duodenum it reaches to pancreas.

Pancreas produces pancreatic juice and this pancreatic juice contains chemical called sodium bicarbonate which acts neutralizer of acid in stomach.

Enzymes like trypsin, chymotrypsin and lipase also start their action in this area. These enzymes will breakdown proteins to peptides and fats to glycerol and fatty acids respectively.

Trypsin cleaves peptide bonds on the C-terminal side of arginines and lysines

Chymotrypsin cuts on the C-terminal side of tyrosine, phenylalanine, and tryptophan residues

Pepsin initiates protein digestion by splitting certain amino acid linkages in proteins to yield peptide fragments.

           Polypeptide                                                       Polypeptide fragments

Next major portion for digestion is the liver. Liver produces bile which emulsifies fats. It will also acts as storage place for glucose as glycogen form. Liver can convert toxic ammonia to less toxic urea.

Once digestion process completes in liver the digested food reaches to small intestine. In this area peptidases and maltase enzymes starts their enzymatic action. Peptidases digest peptides to amino acids and maltase can digests disaccharides.

Summary of chemical digestion process