BS Bachelor of Science: Science of Nutrition 2

Question 1

Which enzyme is responsible for the initial digestion of starch in the mouth?

Accepted Answer

Salivary amylase

Answer

Salivary amylase (ptyalin) begins carbohydrate digestion in the oral cavity by cleaving alpha-1,4-glycosidic bonds in starch.

Question 2

The thermic effect of food (TEF) accounts for approximately what percentage of total daily energy expenditure?

Accepted Answer

5-10%

Answer

TEF typically represents about 5-10% of total energy expenditure and reflects the energy cost of digesting, absorbing, and metabolizing nutrients.

Question 3

Which lipoprotein is primarily responsible for transporting cholesterol from peripheral tissues back to the liver?

Accepted Answer

HDL

Answer

HDL (high-density lipoprotein) performs reverse cholesterol transport, collecting excess cholesterol from peripheral tissues and returning it to the liver.

Question 4

Iron absorption is significantly enhanced by which co-factor consumed in the same meal?

Accepted Answer

Vitamin C

Answer

Vitamin C (ascorbic acid) reduces ferric iron (Fe³⁺) to ferrous iron (Fe²⁺), which is more readily absorbed by intestinal enterocytes.

Question 5

Which amino acids are classified as conditionally essential during periods of physiological stress or illness?

Accepted Answer

Glutamine and arginine

Answer

Glutamine and arginine become conditionally essential during critical illness or surgery because endogenous synthesis cannot meet the body's elevated demands.

BS - Bachelor of Science Practice Test

BS - Bachelor of Science Practice Test

BS Bachelor of Science: Science of Nutrition 2