What type of digestion occur in small intestine?

Answer 1

The duodenum is where breakdown begins in the small intestine and the jejunum is where nutrient absorption "completes." The small intestine receives secretions from the liver and the pancreas. The half-digedted food from the stomach is acidic due to the hydrochloric acid produced by the stomach. In the small intestine, bile from the liver makes it alkaline (basic) so that the pancreatic juices can act on the food. Bile also acts on fats, which exist as fat globules, and breaks them into smaller globules. This is called emulsification of fats. The pancreas releases trypsin, lipase and some other enzymes into the small intestine. Trypsin acts on proteins and lipase acts on emulsified fats. Finally, some intestinal juices secreted by the small intestine itself convert the proteins into amino acids, carbohydrates into glucose and fats into fatty acids and glycerol. All these are absorbed by tiny finger-like projections in the small intestine, called the villi, which are well supplied with blood vessels.

Answer 2

The amount of chemical digestion that occurs in your small intestine depends on your diet. Digestion starts in your mouth. There your teeth perform mechanical digestion and your saliva and thrush starts digesting carbohydrates. In your stomach, you start digesting protein from meat and plant sources. Your small intestine adds chemicals to digest fats and other stuff. Your large intestine continues digestion by digesting complex starches. If you are a vegetarian, about 2/3 of your digestion occurs in your small intestine. If you eat a standard American diet, less than 1/2 of your digestion occurs in your small intestine.

Answer 3

As food travels through the digestive system of animals, it undergoes a series of physical and chemical changes that break it down to provide energy for cells. Physical changes simply alter the appearance of something. For example, chewing breaks large food molecules into smaller ones. In contrast, chemical changes occur when the chemical make-up of the food particle is changed to create a new substance. During the digestive process, enzymes change carbohydrates, proteins, fats and nucleic acids into substances that can be absorbed by cells.

Carbohydrates

Carbohydrate digestion originates in the mouth. The salivary glands secrete saliva, which contains an enzyme called salivary amylase that starts the process of turning the starch found in carbohydrates into a simple sugar. This process is completed in the small intestine when an enzyme, pancreatic amylase, changes starch into the disaccharide maltose, a sugar made of two glucose molecules bonded together. The enzyme maltase splits these two glucose molecules apart. The enzyme lactase breaks down milk sugar, and the enzyme sucrase breaks down table sugar.

Proteins

Protein digestion begins in the stomach. This organ secretes mucus, hydrochloric acid and the enzyme pepsin. The mucus protects the stomach lining, and the acid continues to grind the food into smaller particles. Pepsin splits the protein's polypeptide chains into smaller polypeptides. Pancreatic enzymes in the small intestine complete protein digestion by breaking the polypeptides into small molecules called amino acids.

Nucleic Acids

Nucleic acids DNA and RNA are broken down during the digestive process as well. These compounds consist of polymers of nucleotides and serve as a genetic blueprint for cells. Enzymes in the small intestine, the nucleases, sever the nucleotides of the DNA and RNA into nitrogen bases, sugars and phosphates.

Fats

Fat digestion begins in the small intestine. Fats are insoluble in water, so the liver produces a digestive juice, bile, that physically breaks fat globules into smaller fat droplets, a process called emulsification. The enzyme lipase splits these fat droplets into fatty acids and glycerol.

Answer 4

It starts with saliva in the mouth. Then the stomach adds hydrochloric acid and other chemicals. It is completed in the small intestine when Bile is added by the liver.

Answer 5

The type of digestion occur in small intestine is duodenum.