Question 1

Which type of glycosidic bond is found in starch, making it digestible by humans?

Accepted Answer

$\alpha$-1,4 glycosidic bond

Question 2

Why can't humans digest cellulose, even though it is made of glucose units?

Accepted Answer

Because cellulose contains $\beta$-1,4 glycosidic bonds, and humans lack the enzyme to hydrolyze them.

Question 3

Which enzyme is responsible for breaking down starch in the human digestive system?

Accepted Answer

Amylase

Question 4

Which of the following best describes the structural difference between starch and cellulose?

Accepted Answer

Starch has $\alpha$-1,4 glycosidic bonds, while cellulose has $\beta$-1,4 glycosidic bonds.

Question 5

A patient is unable to digest a certain plant-based polysaccharide. Which bond is most likely present in this polysaccharide?

Accepted Answer

$\beta$-1,4$

Question 6

Which of the following statements is TRUE regarding the digestibility of starch and cellulose in humans?

Accepted Answer

Humans can digest starch but not cellulose because only starch contains $\alpha$-1,4 glycosidic bonds.

Question 7

Which of the following best explains why cellulose serves as dietary fiber in the human diet?

Accepted Answer

Humans lack the enzyme to hydrolyze $\beta$-1,4 glycosidic bonds in cellulose.

Question 8

Which of the following is a correct comparison of the structures of starch and cellulose?

Accepted Answer

Both are composed of glucose units, but starch has $\alpha$-1,4 linkages and cellulose has $\beta$-1,4 linkages.

Question 9

Which of the following would most likely be found in the cell wall of plants and is indigestible by humans?

Accepted Answer

Cellulose

Question 10

A scientist is engineering a new enzyme for humans to digest cellulose. Which bond must this enzyme be able to hydrolyze?

Accepted Answer

$\beta$-1,4$

Question 11

Which of the following best describes the role of $\alpha$-1,4 glycosidic bonds in human nutrition?

Accepted Answer

They are found in starch and can be digested by human enzymes.

Question 12

Which of the following is a direct consequence of the presence of $\beta$-1,4 glycosidic bonds in cellulose?

Accepted Answer

Cellulose forms a rigid structure in plant cell walls.

Comparison of Starch and Cellulose: Structure and Digestibility

Study Guide - Practice Questions