Question

List the chemical changes that starch molecule undergoes from the time it reaches the small intestine.

Answer 1

In the small intestine, starch digestion gets completed. The pancreatic juice contains pancreatic amylases which acts on polysaccharide and convert into disaccharides (maltose). These cretions of the Brunner’s gland along with the secretions of the intestinal glands constitute the intestinal juice or succus entericus. It contains maltose, lactose and sucrose. These convert maltose, lactose and sucrose into monosaccharides, glucose and fructose.

\[\ce{Maltose ->[Maltase]\underset{\text{glucose}}{glucose +}}\]

\[\ce{Sucrose ->[Sucrase]\underset{\text{fructose}}{glucose +}}\]

\[\ce{Lactose ->[Lactase]\underset{\text{galacose}}{glucose +}}\]

In the small intestine, complex carbohydrates are converted into simple ghicose. fructose and galactose. These are absorbed by active transport.