Question

The part of food that is not digested in the body is:
A. Starch
B. Cellulose
C. Protein
D. Fats

Answer 1

Hint: The digestive system of Humans has many enzymes, and acids to break down and digest all kinds of different foods (carbohydrates. proteins and fats), but do not have the enzymes needed to break down cellulose.

Complete Answer:
Carbohydrates, fats, and proteins are the major nutrients the body requires for growth, repair, movement, and maintaining tissue and organ function. These macromolecules are separated and assimilated into the body at different rates and into specific forms as they travel through the organs in the digestive system.
• Protein absorption happens in the stomach and the duodenum through the activity of three principle proteins: pepsin, emitted by the stomach, and trypsin and chymotrypsin, discharged by the pancreas.
• During carbohydrates absorption the bonds between glucose atoms are broken by salivary and pancreatic amylase.
• The absorption of specific fats starts in the mouth, where short-chain lipids separate into diglycerides due to lingual lipase. The fat present in the small digestive tract animates the arrival of lipase from the pancreas, and bile from the liver enabling the breakdown of fats into unsaturated fats.

- Cellulose is a linear polysaccharide polymer with numerous glucose monosaccharide units. The acetal linkage is beta which makes it not quite the same as starch. This particular contrast in acetal linkages brings about a significant distinction in absorbability in humans. They can't digest cellulose on the grounds that the proper catalysts to break down the beta acetal linkages are deficient.
- Cows, Goats, Sheep and different animals that live on numerous natural and organic food, do have the catalysts expected to separate cellulose.

Hence, the correct answer for this question is B, i.e. Cellulose.

Note: There are particular reactions included in the hydrolysis of the 1,4-beta-D-glycosidic linkages in cellulose, hemicellulose, lichenin, and cereal beta-D-glucans. These catalysts are missing in people, due to which people cannot process cellulose.