Question 1

Which of the following statements best describes the role of glucose in human metabolism?

Accepted Answer

Glucose is the most abundant monosaccharide and serves as the primary energy source for cells, especially red blood cells and neurons.

Question 2

Which of the following is a correct description of an epimer?

Accepted Answer

Isomers that differ only in the configuration around one specific carbon atom.

Question 3

What is the minimum daily intake of carbohydrates required to prevent ketosis in adults?

Accepted Answer

$$50\ g$$

Question 4

Which of the following best explains why cellulose cannot be digested by humans?

Accepted Answer

Cellulose is a polysaccharide with beta(1-4) glycosidic bonds, and humans lack the enzyme to break these bonds.

Question 5

Which transporter is responsible for glucose uptake in the intestinal mucosa and proximal tubule of the nephron?

Accepted Answer

SGLT (Sodium-Glucose Linked Transporter)

Question 6

A patient consumes a meal rich in sucrose. Which monosaccharides will be absorbed after digestion?

Accepted Answer

Glucose and fructose

Question 7

Which of the following correctly describes the difference between anomers?

Accepted Answer

Anomers differ in the configuration around the carbon atom adjacent to the carbonyl group (anomeric carbon) after cyclization.

Question 8

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

Accepted Answer

$$C_n(H_2O)_n$$

Question 9

Which polysaccharide is the main storage form of carbohydrates in animals, and what type of glycosidic bonds does it contain?

Accepted Answer

Glycogen; alpha(1-4) and alpha(1-6) glycosidic bonds

Question 10

How many possible optical isomers exist for an aldohexose?

Accepted Answer

$$2^n$$, where $$n is $$the number of asymmetric carbons; for aldohexose, $$n=4$$, so $$2^4=16$

Question 11

Which of the following statements about dietary fiber is correct?

Accepted Answer

Dietary fiber is not digested by human enzymes, contributes to gut health, and provides about 2 kcal/g.

Question 12

Which enzyme is responsible for the hydrolysis of starch in the human digestive tract?

Accepted Answer

Amylase

Question 13

Which of the following is a correct statement about the GLUT4 transporter?

Accepted Answer

GLUT4 is activated by insulin and is found in muscle and adipose tissue.

Question 14

Which of the following disaccharides is formed by a beta(1-4) glycosidic bond between galactose and glucose?

Accepted Answer

Lactose

Question 15

A patient with a deficiency in lactase will have difficulty digesting which carbohydrate?

Accepted Answer

Lactose

Question 16

Which of the following statements about fructose is correct?

Accepted Answer

Fructose is a ketohexose, has greater sweetening power than glucose, and is converted to glucose in the liver.

Question 17

Which of the following is a correct description of the glycosidic bond formation?

Accepted Answer

A glycosidic bond forms between the hydroxyl group of one monosaccharide and the anomeric carbon of another, releasing a molecule of water.

Question 18

Which of the following is a function of polysaccharides in living organisms?

Accepted Answer

Polysaccharides serve as both energy reserves (e.g., glycogen, starch) and structural components (e.g., cellulose, chitin).

Question 19

During glycolysis, what is the net production of ATP per molecule of glucose?

Accepted Answer

$$2$$

Carbohydrates: Structure, Classification, Stereochemistry, and Metabolism

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