Nutritional Biochemistry and Supplementation Flashcards

Which form of magnesium is most often used clinically for its muscle-relaxing and sleep-supporting properties?

Answer: Magnesium glycinate

Magnesium glycinate is chelated to glycine, an inhibitory neurotransmitter, producing calming effects that support sleep and muscle relaxation with minimal laxative side effects.

What is the mechanism by which probiotics improve intestinal barrier function in clinical nutrition?

Answer: Upregulating tight junction protein expression (occludin, claudin) and reducing intestinal permeability

Probiotic strains stimulate expression of tight junction proteins that seal paracellular spaces, reducing 'leaky gut,' modulating immune responses, and decreasing translocation of harmful bacteria.

Berberine is a plant alkaloid used as a nutraceutical that exerts metabolic effects through which primary mechanism?

Answer: Activation of AMP-activated protein kinase (AMPK), improving insulin sensitivity and lipid metabolism

Berberine activates AMPK, an energy sensor that increases glucose uptake, fatty acid oxidation, and insulin sensitivity while inhibiting gluconeogenesis and lipogenesis.

What is the clinical significance of the ratio between omega-6 and omega-3 fatty acids in the Western diet?

Answer: High omega-6:omega-3 ratio (15-20:1) promotes pro-inflammatory eicosanoid production, linked to chronic disease

The Western diet ratio of 15-20:1 favors arachidonic acid-derived pro-inflammatory eicosanoids (prostaglandins, leukotrienes); optimal health is associated with ratios closer to 4:1 or lower.

N-acetylcysteine (NAC) is used as a supplement primarily because it is a precursor to which endogenous antioxidant?

Answer: Glutathione (GSH)

NAC provides cysteine, the rate-limiting substrate for glutathione synthesis, replenishing this critical intracellular antioxidant and detoxification cofactor.

Which enzyme converts linoleic acid (omega-6) and alpha-linolenic acid (omega-3) to their longer-chain derivatives?

Answer: Delta-6 desaturase

Delta-6 desaturase is the rate-limiting enzyme for elongating and desaturating ALA to EPA/DHA and linoleic acid to arachidonic acid; it is inhibited by trans fats, high glucose, and aging.