Macronutrient Science Flashcards

Which fatty acid classification describes fats with two or more double bonds in their carbon chain?

Answer: Polyunsaturated fatty acids

Polyunsaturated fatty acids (PUFAs) contain two or more carbon-carbon double bonds, making them liquid at room temperature and prone to oxidation.

A client following a ketogenic diet is in nutritional ketosis. Which ketone body is produced in the greatest quantity?

Answer: Beta-hydroxybutyrate

Beta-hydroxybutyrate (BHB) is the most abundant ketone in the blood during nutritional ketosis, comprising roughly 70-75% of circulating ketones.

The glycemic index of a food is measured relative to which reference food?

Answer: Glucose

Glycemic index is defined relative to pure glucose (GI = 100), though white bread is sometimes used as an alternative reference in some systems.

Which enzyme is responsible for the rate-limiting step in fatty acid synthesis?

Answer: Acetyl-CoA carboxylase (ACC)

Acetyl-CoA carboxylase (ACC) catalyzes the conversion of acetyl-CoA to malonyl-CoA, which is the committed and rate-limiting step in de novo lipogenesis.

When coaching an athlete for muscle gain, what approximate protein distribution per meal optimizes muscle protein synthesis across the day?

Answer: Distributing 30-40g of protein across 4-5 meals evenly

Evenly distributing 30-40g of high-quality protein across multiple meals maximizes the total 24-hour MPS response compared to skewed distribution.

Which monosaccharide is the primary fuel for red blood cells?

Answer: Glucose

Red blood cells lack mitochondria and rely exclusively on anaerobic glycolysis using glucose as their sole energy substrate.

A high-protein diet consistently above 2.2g/kg has been shown to cause kidney damage in:

Answer: Individuals with pre-existing kidney disease

High protein intake can accelerate progression of existing kidney disease, but current evidence does not support harm in healthy individuals with normal kidney function.