NTP NTP Detoxification & Metabolic Health 1 — Questions and Answers
Question 1: Which organ is the primary site of Phase I and Phase II detoxification reactions in the human body?
- Kidneys
- Liver (Correct answer)
- Lungs
- Skin
Correct answer: Liver
The liver is the central detoxification organ, housing the cytochrome P450 enzymes of Phase I and conjugation enzymes of Phase II.
Question 2: Phase I detoxification primarily uses which enzyme system to begin transforming toxins?
- Sulfotransferases
- Cytochrome P450 enzymes (Correct answer)
- Glutathione S-transferases
- UDP-glucuronyltransferases
Correct answer: Cytochrome P450 enzymes
Cytochrome P450 enzymes catalyze oxidation, reduction, and hydrolysis reactions in Phase I, often making toxins temporarily more reactive.
Question 3: Which amino acid is the precursor to glutathione, the body's primary endogenous antioxidant used in Phase II detoxification?
- Tryptophan
- Cysteine (Correct answer)
- Lysine
- Arginine
Correct answer: Cysteine
Cysteine provides the rate-limiting sulfhydryl group for glutathione synthesis, making it the key precursor for this tripeptide antioxidant.
Question 4: Which Phase II detox pathway conjugates toxins with sulfate groups and is commonly assessed by measuring sulfate availability?
- Glucuronidation
- Methylation
- Sulfation (Correct answer)
- Acetylation
Correct answer: Sulfation
Sulfation involves the transfer of a sulfate group to toxins, drugs, and hormones to facilitate their excretion, and requires adequate sulfur intake from dietary sources.
Question 5: A client on a nutritional detox protocol should prioritize which foods to support glutathione production?
- White rice and pasta
- Cruciferous vegetables, garlic, and onions (Correct answer)
- Dairy and eggs only
- Processed soy products
Correct answer: Cruciferous vegetables, garlic, and onions
Cruciferous vegetables provide glucosinolates that upregulate detox enzymes, while garlic and onions provide sulfur compounds that support glutathione synthesis.
Question 6: Which nutrient is essential as a methyl donor for the methylation Phase II detox pathway?
- Vitamin C
- Folate (5-MTHF) and B12 (Correct answer)
- Zinc
- Vitamin A
Correct answer: Folate (5-MTHF) and B12
Methylation requires folate (as 5-MTHF) and B12 to donate methyl groups for detoxifying heavy metals, hormones, and neurotransmitters.
NTP NTP Detoxification & Metabolic Health 1
Which organ is the primary site of Phase I and Phase II detoxification reactions in the human body?