Fundamentals of Nutrition Science Flashcards
7 cards from real CNC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Fundamentals of Nutrition Science flashcards as text
Which vitamin is synthesized in the skin upon exposure to ultraviolet B (UVB) radiation and functions as a prohormone regulating calcium absorption?
Answer: Vitamin D
UVB radiation converts 7-dehydrocholesterol in the skin to vitamin D3 (cholecalciferol), which is then activated in the liver and kidneys to regulate intestinal calcium absorption.
The essential amino acid that serves as a precursor to serotonin and melatonin synthesis is:
Answer: Tryptophan
Tryptophan is hydroxylated to 5-hydroxytryptophan (5-HTP) and then decarboxylated to serotonin, which can further be converted to melatonin in the pineal gland.
In the context of energy balance, what term describes the energy expenditure associated with non-exercise physical activity such as fidgeting, posture, and daily movement?
Answer: NEAT (Non-Exercise Activity Thermogenesis)
NEAT encompasses all energy spent on physical activity that is not structured exercise, and can vary by up to 2,000 kcal/day between sedentary and active individuals.
Which mineral is required for the synthesis of thyroid hormones T3 and T4, and its deficiency results in goiter?
Answer: Iodine
Iodine is incorporated into thyroxine (T4) and triiodothyronine (T3) by the thyroid gland; deficiency causes the gland to enlarge (goiter) in an effort to trap more iodine.
The concept of 'nitrogen balance' is used to assess protein metabolism. A negative nitrogen balance indicates that:
Answer: Protein breakdown exceeds protein synthesis
Negative nitrogen balance occurs when nitrogen excretion (via urine, feces, skin) exceeds nitrogen intake, indicating net protein catabolism greater than anabolism.
Which type of carbohydrate is NOT digested by human enzymes but selectively feeds beneficial gut bacteria, classifying it as a prebiotic?
Answer: Fructooligosaccharides (FOS)
Fructooligosaccharides resist digestion in the small intestine and reach the colon intact, where they are selectively fermented by beneficial bacteria such as Bifidobacterium.
A client following a strict vegan diet is most at risk for deficiency in which nutrient that is found almost exclusively in animal products?
Answer: Vitamin B12
Vitamin B12 (cobalamin) is produced only by microorganisms and is found in meaningful quantities almost exclusively in animal-derived foods, making supplementation essential for vegans.