NTA Nutritional Science Fundamentals 3 — Questions and Answers
Question 1: Which pathway is the body's primary mechanism for producing glucose from non-carbohydrate substrates such as amino acids and glycerol?
- Glycolysis
- Gluconeogenesis (Correct answer)
- Glycogenolysis
- Beta-oxidation
Correct answer: Gluconeogenesis
Gluconeogenesis is the metabolic pathway that synthesizes glucose from non-carbohydrate precursors, primarily occurring in the liver and to a lesser extent in the kidneys.
Question 2: What is the glycemic index (GI) of a food primarily determined by?
- The total carbohydrate content in grams per serving
- The rate at which the food raises blood glucose compared to a reference food (Correct answer)
- The fiber content relative to total carbohydrates
- The fructose-to-glucose ratio of the carbohydrates present
Correct answer: The rate at which the food raises blood glucose compared to a reference food
The glycemic index measures how quickly a food raises blood glucose levels compared to a reference food (usually pure glucose or white bread = 100), expressed as a percentage.
Question 3: Which lipoprotein is responsible for transporting dietary fat from the intestines via the lymphatic system to peripheral tissues?
- LDL
- HDL
- VLDL
- Chylomicron (Correct answer)
Correct answer: Chylomicron
Chylomicrons, assembled in intestinal enterocytes, carry dietary triglycerides and fat-soluble vitamins through the lymphatic system before entering the bloodstream.
Question 4: What is the role of intrinsic factor in nutritional absorption?
- It activates vitamin D in the kidneys
- It binds vitamin B12 in the stomach, enabling its absorption in the ileum (Correct answer)
- It facilitates iron absorption in the duodenum
- It stimulates bile release from the gallbladder
Correct answer: It binds vitamin B12 in the stomach, enabling its absorption in the ileum
Intrinsic factor is a glycoprotein secreted by gastric parietal cells that binds vitamin B12 and carries it to specific receptors in the terminal ileum for absorption.
Question 5: Which of the following best describes the concept of 'nitrogen balance'?
- The ratio of protein to fat in the diet
- The difference between nitrogen intake and nitrogen excreted (Correct answer)
- The amount of nitrogen stored in muscle tissue
- The proportion of dietary protein converted to urea
Correct answer: The difference between nitrogen intake and nitrogen excreted
Nitrogen balance compares the amount of nitrogen consumed (primarily from protein) to the amount excreted, indicating whether the body is building, maintaining, or breaking down protein.
Question 6: What is the primary function of the hormone cholecystokinin (CCK) in digestion?
- Stimulating gastric acid secretion
- Triggering gallbladder contraction and pancreatic enzyme release (Correct answer)
- Reducing intestinal motility to slow digestion
- Promoting water absorption in the large intestine
Correct answer: Triggering gallbladder contraction and pancreatic enzyme release
CCK is released by duodenal cells in response to fat and protein, stimulating gallbladder contraction to release bile and triggering pancreatic enzyme secretion.
Question 7: In the NTA framework, which of the following is considered a 'Foundational Physiological Principle' that underlies nutrient utilization?
- Caloric restriction as the primary health intervention
- Digestion, absorption, and elimination as prerequisites for nutrient benefit (Correct answer)
- Supplementation as equivalent to whole-food nutrition
- Macronutrient ratios as the sole determinant of health
Correct answer: Digestion, absorption, and elimination as prerequisites for nutrient benefit
The NTA emphasizes that digestion, absorption, and elimination must be functioning optimally before nutrients can provide benefit, regardless of dietary quality.
NTA Nutritional Science Fundamentals 3
Which pathway is the body's primary mechanism for producing glucose from non-carbohydrate substrates such as amino acids and glycerol?