how does mechanical digestion occur in the small intestine?

What three enzymes are involved in chemical digestion of small intestine and what 3 sugars do they break down?

Mechanical digestion in the small intestine occurs through the coordinated movement of the intestinal muscles, which mix and propels the food. This process is known as peristalsis. When the food bolus enters the small intestine from the stomach through the pyloric sphincter, it is broken down into smaller pieces through the churning action of the intestinal muscles. This helps increase the surface area of the food, facilitating the absorption of nutrients.

As for the chemical digestion in the small intestine, there are three main enzymes involved:

1. Pancreatic Amylase: Secreted by the pancreas, pancreatic amylase breaks down complex carbohydrates into smaller sugar molecules, mainly maltose (a disaccharide).

2. Sucrase: Produced by the brush border cells in the small intestine, sucrase is responsible for breaking down the disaccharide sucrose (table sugar) into glucose and fructose.

3. Lactase: Also produced by the brush border cells, lactase is involved in breaking down the disaccharide lactose (found in milk and dairy products) into glucose and galactose.

These enzymes play a crucial role in breaking down complex carbohydrates into simpler sugars, which can then be absorbed into the bloodstream through the lining of the small intestine.

Mechanical digestion in the small intestine occurs through a process called segmentation. Segmentation involves the contraction and relaxation of the smooth muscles in the intestinal wall, which helps mix and propel the food forward, allowing for better absorption and exposure to the digestive enzymes.

The three enzymes involved in chemical digestion in the small intestine are:

1. Pancreatic amylase: This enzyme is secreted by the pancreas and breaks down complex carbohydrates (starches and glycogen) into smaller sugar molecules.

2. Peptidases: These enzymes, including trypsin, chymotrypsin, and carboxypeptidase, are also secreted by the pancreas. They break down proteins into smaller peptide fragments.

3. Intestinal disaccharidases: These enzymes are located on the surface of the small intestine lining and include lactase, sucrase, and maltase. They break down disaccharides (double sugar molecules) into monosaccharides.

The three sugars that these enzymes break down are:

1. Lactase breaks down lactose (a sugar found in milk) into glucose and galactose.

2. Sucrase breaks down sucrose (table sugar) into glucose and fructose.

3. Maltase breaks down maltose (a sugar produced during starch digestion) into two glucose molecules.