Biology 2.4 Carbohydrate Digestion

Starch digestion

Specific enzymes break down large molecules into sections, and other enzymes break the sections down into monomers.

Enzymes usually produced in different parts of digestive system (different optimum pH), so need correct sequence.

In humans starch is digested as follows:

• Food taken into mouth, chewed by teeth = small pieces, large surface area.
• Salive enters mouth from salivary glands, mixed with food by chewing.
• Salivary amylase = hydrolyses starch into maltose, saliva containes minerals that maintain pH at around neutral (optimum for salivary amylase).
• Food is swallowed, enters stomach, conditions are acidic, denatures amylase and prevents further hydrolysis of starch.
• Food passed into small intestine - mixed with pancreatic juice from the pancreas.
• Pancreatic amylase continues hydrolysis…