NTP Macronutrient & Micronutrient Science 2 — Questions and Answers
Question 1: Which fatty acid is classified as an omega-6 and is considered essential because humans cannot synthesize it?
- Alpha-linolenic acid
- Linoleic acid (Correct answer)
- Arachidonic acid
- Eicosapentaenoic acid
Correct answer: Linoleic acid
Linoleic acid (18:2 n-6) is the essential omega-6 fatty acid that must be obtained from the diet.
Question 2: What is the primary role of chromium as a micronutrient in human metabolism?
- Oxygen transport in red blood cells
- Potentiating insulin signaling and glucose uptake (Correct answer)
- Bone mineralization alongside calcium
- Thyroid hormone synthesis
Correct answer: Potentiating insulin signaling and glucose uptake
Chromium enhances insulin receptor sensitivity, facilitating glucose uptake into cells.
Question 3: In the context of protein quality, what does a PDCAAS score of 1.0 indicate?
- The protein contains no essential amino acids
- The protein meets or exceeds all essential amino acid requirements after digestibility correction (Correct answer)
- The protein has 100g of amino acids per serving
- The protein is entirely absorbed in the large intestine
Correct answer: The protein meets or exceeds all essential amino acid requirements after digestibility correction
A PDCAAS of 1.0 (the maximum score) means the protein fully meets human essential amino acid needs when digestibility is accounted for.
Question 4: Which vitamin is unique in that it can be synthesized by humans through skin exposure to ultraviolet B radiation?
- Vitamin A
- Vitamin K
- Vitamin D (Correct answer)
- Vitamin E
Correct answer: Vitamin D
Vitamin D3 (cholecalciferol) is synthesized in the skin when 7-dehydrocholesterol is converted upon UVB exposure.
Question 5: What metabolic fate do excess dietary carbohydrates primarily take when glycogen stores are full?
- Excretion in urine as glucose
- Conversion to fatty acids via de novo lipogenesis (Correct answer)
- Direct conversion to protein
- Stored as glycogen in the pancreas
Correct answer: Conversion to fatty acids via de novo lipogenesis
When glycogen stores are saturated, excess carbohydrates undergo de novo lipogenesis primarily in the liver, forming fatty acids.
Question 6: Which mineral is a cofactor for over 300 enzymatic reactions and is critical for ATP synthesis and protein production?
- Iron
- Zinc
- Magnesium (Correct answer)
- Copper
Correct answer: Magnesium
Magnesium is required by over 300 enzymes, including those involved in ATP hydrolysis, DNA synthesis, and protein metabolism.
Question 7: A client consumes a diet very high in raw egg whites. Which B-vitamin deficiency could result over time, and why?
- Thiamine, because avidin blocks thiamine absorption
- Biotin, because avidin in raw egg whites binds biotin and prevents its absorption (Correct answer)
- Riboflavin, because albumin competes with riboflavin transporters
- Niacin, because egg whites lack tryptophan
Correct answer: Biotin, because avidin in raw egg whites binds biotin and prevents its absorption
Avidin, a glycoprotein in raw egg whites, tightly binds biotin in the gut and prevents its absorption, potentially causing biotin deficiency.
NTP Macronutrient & Micronutrient Science 2
Which fatty acid is classified as an omega-6 and is considered essential because humans cannot synthesize it?