Digestion And Absorption Of Carbohydrates

Digestion And Absorption Of Carbohydrates

Discuss digestion and absorption of carbohydrates in the gastrointestinal tract.
Answer:

Digestion of carbohydrates:

1. In the mouth:

1. During mastication, salivary amylase acts on starch and causes breakage of the a-glycosidic bond.
2. Products formed are dextrins, maltotriose, and maltose.

“Understanding carbohydrate digestion through FAQs: Enzymes, processes, and uses explained”

2. In the stomach:

• Carbohydrate is not digested in the stomach due to the high acidity present in them.

3. In the intestine:

1. The acidic constituents from the stomach are neutralized by the bicarbonate content of the pancreas.
2. The pancreatic amylase acts and a-1, 4 -glycosidic bonds of starch and causes its breakage.
3. The resultant products are disaccharides and oligosaccharides.
4. The enzyme oligosaccharides act on oligosaccharides and disaccharidases act on disaccharides.
5. This converts both these carbohydrates to monosaccharides.
6. It occurs at the mucosal lining of the upper jejunum.

“Importance of studying carbohydrate digestion for medical students: Questions explained”

Absorption of carbohydrates:

• Monosaccharides produced by digestion are glucose – 80%, fructose, and lactose.
• The absorption takes place in the duodenum and upper jejunum.

1. Absorption of glucose:

• Glucose is transported by means of sodium co-transport.
• Glucose first combines with a carrier and forms glucose- a carrier complex.
• This moves the glucose across the cell membrane and releases glucose inside the cell.
• The glucose and Na+ have the same carrier called sodium-dependent glucose transporter.
• To concentrate the glucose within the cell, the carrier is coupled to a source of energy which is obtained by the binding process of sodium ion and glucose molecule to the carrier protein.
• The glucose is then transported into the interstitial space and then the blood capillaries.

“Common challenges in mastering carbohydrate digestion notes effectively: FAQs provided”

2. Absorption of fructose:

• Fructose is transported by facilitated diffusion mediated by a carrier.
• Inside the cell, most of it is converted to glucose.

Digestion and absorption of carbohydrates

3. Absorption of pentoses:

• Occurs by simple diffusion.