Question

cellulose is a major component of the tough cell walls in plant cells. it is formed from glucose monomers and has 1 - 4 glycosidic linkages. a glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another carbohydrate. the 1,4 glycosidic bond is formed between the carbon - 1 of one monosaccharide and carbon - 4 of the other monosaccharide. similar to cellulose, starch is also comprised of 1 - 4 glycosidic linkages between glucose monomers. if this is true, then how are starch and cellulose structurally different? examine the image below to answer questions 9 - 10.
starch
glucose monomers with their hydroxyl group in this position are known as alpha glucose monomers
glucose monomers with their hydroxyl group in this position are known as beta glucose monomers
cellulose

1. what structural differences can be found between starch and cellulose?
2. explain and justify how the structural differences between starch and cellulose lead to functional differences in plants.
3. some nutritional labels for plant - based food may include an “insoluble fiber” category. insoluble fiber is in reference to cellulose and is also called “roughage.” cellulose is considered insoluble because humans cannot digest it. however, cellulose is still recommended to be consumed as a part of a healthy diet. why might this be? to answer this question research insoluble fiber on your own and record your findings here before formulating a well - written response.

dietary fiber 5g 18%
soluble fiber 2g
insoluble fiber 3g

Explanation:

1. Starch is made of alpha - glucose monomers and has a branched structure in some forms. Cellulose is made of beta - glucose monomers and forms straight, parallel chains that can hydrogen - bond with each other to form tough fibers.
2. The branched structure of starch allows it to be easily broken down by enzymes for energy storage and release in plants. The straight - chain, hydrogen - bonded structure of cellulose provides structural support to plant cell walls, making them rigid and able to maintain cell shape and resist mechanical stress.
3. Although humans can't digest cellulose, it acts as insoluble fiber in the diet. It adds bulk to the feces, promoting regular bowel movements, preventing constipation, and may also help in reducing the risk of certain digestive disorders by keeping the digestive tract healthy.

Answer:

1. Starch has alpha - glucose monomers and can be branched; cellulose has beta - glucose monomers and forms straight, hydrogen - bonded chains.
2. Starch's branched structure aids energy storage/release; cellulose's straight - chain, hydrogen - bonded structure provides structural support.
3. It acts as insoluble fiber, promotes bowel health, and may reduce digestive disorder risks.