Chemical digestion of starch

Chemical digestion of starch occurs in the following steps:

1. Ingestion: The process begins when you consume a food item containing starch.

2. Mechanical Digestion in the Mouth: The food is broken down into smaller pieces by the teeth during mastication (chewing). Saliva, produced by the salivary glands, is mixed with these smaller pieces of food during this process.

3. Chemical Digestion in the Mouth: Saliva contains an enzyme called salivary amylase, which begins the process of breaking down the starch molecules in the food into smaller molecules.

4. Digestion in the Stomach: The food then travels down the esophagus and into the stomach, where it is mixed with stomach acid and enzymes. However, these enzymes do not break down starch.

5. Digestion in the Small Intestine: The partially digested food then moves into the small intestine. Here, it mixes with pancreatic amylase, an enzyme produced by the pancreas that continues the breakdown of starch into maltose, a smaller carbohydrate.

6. Final Digestion and Absorption: The cells lining the small intestine produce enzymes called maltase, sucrase, and lactase. Maltase completes the digestion of maltose into glucose, which can be absorbed into the bloodstream and used by the body for energy.

So, the chemical digestion of starch involves the breakdown of large starch molecules into smaller carbohydrates and ultimately into glucose, which can be absorbed and used by the body. This process involves several different enzymes, each of which is necessary for the complete digestion of starch.