Question 1

Which of the following best describes the process of photosynthesis in plants?

Accepted Answer

It converts carbon dioxide and water into glucose and oxygen using energy from the sun.

Question 2

Which of the following is a correct general formula for carbohydrates?

Accepted Answer

$$C_xH_yO_z$$

Question 3

A monosaccharide with the formula $$C_6H_{12}O_6$ and a ketone functional group is classified as:

Accepted Answer

A ketohexose

Question 4

Which of the following statements about Fischer projections is TRUE?

Accepted Answer

Vertical lines represent bonds going behind the plane of the paper.

Question 5

Which of the following best describes a chiral carbon?

Accepted Answer

A carbon atom with four different groups attached.

Question 6

In the D-enantiomer of a carbohydrate, the –OH group on the chiral carbon farthest from the carbonyl group is oriented:

Accepted Answer

To the right

Question 7

Which of the following is TRUE about D-glucose?

Accepted Answer

It is an aldohexose and is the main sugar measured in blood sugar tests.

Question 8

A patient’s fasting blood glucose level is measured at 135 mg/dL on two separate occasions. According to clinical guidelines, what is the most likely diagnosis?

Accepted Answer

Diabetes

Question 9

Which of the following statements about mutarotation is correct?

Accepted Answer

It is the equilibrium between the α and β anomers of a cyclic sugar in solution.

Question 10

Which of the following sugars is NOT a reducing sugar?

Accepted Answer

Sucrose

Question 11

Which of the following best explains why sucrose does NOT give a positive Benedict’s test?

Accepted Answer

Both anomeric carbons are involved in the glycosidic bond, so no free hemiacetal or hemiketal group is present.

Question 12

Which of the following is the correct product of the reduction of D-glucose?

Accepted Answer

D-glucitol (D-sorbitol)

Question 13

Which of the following polysaccharides is unbranched and contains β-(1,4)-glycosidic bonds?

Accepted Answer

Cellulose

Question 14

Which of the following best describes the structure of glycogen?

Accepted Answer

It is a branched polymer of glucose with α-(1,4)- and α-(1,6)-glycosidic bonds, with branches every 10–15 units.

Question 15

Which of the following statements about the digestion of polysaccharides in humans is correct?

Accepted Answer

Humans can digest starch because they have enzymes for α-(1,4)-glycosidic bonds.

Question 16

Which of the following is a correct description of lactose?

Accepted Answer

A disaccharide of galactose and glucose with a β-(1,4)-glycosidic bond.

Question 17

Which of the following best describes the difference between amylose and amylopectin?

Accepted Answer

Amylose is unbranched, while amylopectin is branched with α-(1,6)-glycosidic bonds.

Question 18

Which of the following is a real-life consequence of the accumulation of D-sorbitol in the lens of the eye in diabetics?

Accepted Answer

Cataracts

Question 19

Which of the following best describes the glycosidic linkage in maltose?

Accepted Answer

α-(1,4)-glycosidic bond between two D-glucose units

Question 20

Which of the following statements about the Benedict’s test is correct?

Accepted Answer

A positive result is indicated by a red/orange precipitate, showing the presence of reducing sugars.

Carbohydrates: Structure, Classification, and Biological Importance

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