Correct Answer: D

Rationale: The correct answer is D, eggs. Eggs are considered a high-quality protein source as they are rich in indispensable amino acids. Lentils, tofu, and peanuts also contain protein but are not as high in indispensable amino acids as eggs, making them less complete protein sources.

Correct Answer: B

Rationale: The most important monosaccharides in human nutrition are glucose, fructose, and galactose. Galactose is crucial as it is one of the main components of lactose, a disaccharide sugar found in milk. Therefore, choices A, C, and D are incorrect as lactose, maltose, and sucrose are disaccharides composed of two monosaccharide units.

Correct Answer: A

Rationale: The correct answer is A: Forming neurotransmitters. Methionine, tyrosine, and tryptophan are important amino acids involved in the production of neurotransmitters in the body. Neurotransmitters are chemical messengers that transmit signals across nerve cells, influencing various functions such as mood, memory, and muscle control. Choices B, C, and D are incorrect because these amino acids do not primarily play a role in blocking protein breakdown, increasing insulin and thyroxine production, or decreasing energy expenditure.

Correct Answer: C

Rationale: The correct answer is C, kwashiorkor. Kwashiorkor is a type of protein-energy malnutrition characterized by edema, hypoalbuminemia, skin lesions, and fatty liver. Edema is a key feature of kwashiorkor due to hypoalbuminemia, which leads to decreased oncotic pressure. Marasmus (choice B) is a form of severe malnutrition characterized by energy deficiency without significant protein deficiency, resulting in severe wasting. Cachexia (choice A) is a syndrome characterized by weight loss, muscle atrophy, fatigue, weakness, and loss of appetite in someone who is not actively trying to lose weight. Sarcopenia (choice D) is the age-related loss of muscle mass and function.

Correct Answer: B

Rationale: Carbohydrates have a protein-sparing effect, meaning that adequate carbohydrate intake can prevent the use of protein for energy. Glycerol, nitrogen, and fatty acids do not have a protein-sparing effect. Glycerol is a component of fats and oils, nitrogen is a component of proteins, and fatty acids are used primarily as an energy source.