Free CNS Nutritional Biochemistry & Physiology Questions and Answers — Questions and Answers

Question 1: Which vitamin is essential for collagen synthesis and wound healing?

Vitamin A
Vitamin C (Correct answer)
Vitamin D
Vitamin K

Correct answer: Vitamin C

Vitamin C, also known as ascorbic acid, is a powerful antioxidant and an essential nutrient for human health. It plays a critical role as a co-factor in the synthesis of collagen, a vital protein for connective tissues, skin, bones, and blood vessels. This function makes Vitamin C indispensable for wound healing and maintaining tissue integrity.

Question 2: What is the primary function of the enzyme amylase in digestion?

Breaks down proteins
Emulsifies fats
Breaks down starch into maltose (Correct answer)
Absorbs nutrients in the intestines

Correct answer: Breaks down starch into maltose

Amylase is a digestive enzyme primarily produced in the salivary glands and pancreas. Its main function is to initiate the chemical digestion of carbohydrates, specifically breaking down complex starches (polysaccharides) into simpler sugars like maltose (a disaccharide). This process begins in the mouth and continues in the small intestine, preparing carbohydrates for further breakdown and absorption.

Question 3: Which macronutrient is primarily metabolized through beta-oxidation?

Carbohydrates
Proteins
Lipids (Correct answer)
Nucleic acids

Correct answer: Lipids

Beta-oxidation is the specific metabolic pathway responsible for breaking down fatty acids, which are the primary components of lipids. This process occurs in the mitochondria and generates acetyl-CoA, which then enters the citric acid cycle to produce energy (ATP). While carbohydrates and proteins are also energy sources, beta-oxidation is uniquely associated with lipid metabolism.

Question 4: What hormone regulates calcium levels in the blood by increasing calcium absorption in the intestines?

Parathyroid hormone
Calcitonin
Calcitriol (Correct answer)
Insulin

Correct answer: Calcitriol

Calcitriol, the active form of Vitamin D, is the primary hormone that regulates calcium levels by increasing its absorption in the intestines. It stimulates the production of proteins necessary for calcium uptake from the digestive tract into the bloodstream. While other hormones like parathyroid hormone and calcitonin also influence calcium, calcitriol specifically targets intestinal absorption.

Question 5: Which amino acid is considered essential and must be obtained from the diet?

Glutamine
Leucine (Correct answer)
Tyrosine
Alanine

Correct answer: Leucine

Leucine is one of the nine essential amino acids, meaning the human body cannot synthesize it and it must be obtained through dietary intake. It is a branched-chain amino acid (BCAA) particularly vital for muscle protein synthesis, repair, and energy production. Unlike non-essential amino acids, a consistent dietary supply of leucine is critical for proper physiological function.

Question 6: Which vitamin acts as a coenzyme in the metabolism of carbohydrates and amino acids?

Vitamin B1 (Thiamine) (Correct answer)
Vitamin B12 (Cobalamin)
Vitamin E
Vitamin K

Correct answer: Vitamin B1 (Thiamine)

Vitamin B1, also known as Thiamine, acts as a crucial coenzyme in several metabolic pathways, particularly those involved in the metabolism of carbohydrates and branched-chain amino acids. It is essential for converting glucose into energy and plays a vital role in nerve function. Without adequate thiamine, the body's ability to process these macronutrients is impaired.

Question 7: What is the main role of insulin in nutrient metabolism?

Stimulates glucose production
Promotes glucose uptake and glycogen synthesis (Correct answer)
Breaks down fats
Inhibits protein synthesis

Correct answer: Promotes glucose uptake and glycogen synthesis

Insulin's main role in nutrient metabolism is to promote the uptake of glucose from the blood into cells, especially muscle and fat cells, thereby lowering blood sugar levels. It also stimulates the liver and muscles to convert excess glucose into glycogen for storage. This action is crucial for maintaining metabolic homeostasis after consuming carbohydrates.

Question 8: Which mineral is crucial for oxygen transport in the blood?

Zinc
Magnesium
Iron (Correct answer)
Calcium

Correct answer: Iron

Iron is an essential mineral that is crucial for oxygen transport in the blood. It is a key component of hemoglobin, the protein found in red blood cells that binds to and carries oxygen from the lungs to all body tissues. Without sufficient iron, the body cannot produce enough healthy red blood cells, leading to conditions like anemia.

Question 9: Which process describes the synthesis of glucose from non-carbohydrate sources?

Glycolysis
Gluconeogenesis (Correct answer)
Glycogenolysis
Lipolysis

Correct answer: Gluconeogenesis

Gluconeogenesis is the metabolic process by which glucose is synthesized from non-carbohydrate precursors, such as lactate, amino acids, and glycerol. This pathway is essential for maintaining blood glucose levels during periods of fasting, starvation, or intense exercise when carbohydrate intake is insufficient. It ensures a continuous supply of glucose for glucose-dependent organs like the brain.

Free CNS Nutritional Biochemistry & Physiology Questions and Answers

Which vitamin is essential for collagen synthesis and wound healing?