Correct Answer: D

Rationale: The correct answer is D, peptide bond. A peptide bond is formed through a dehydration synthesis reaction between the amine group of one amino acid and the carboxyl group of another amino acid. This bond is crucial in protein synthesis. Choices A, B, and C are incorrect. A double bond involves sharing two pairs of electrons, a hydrogen bond is a weak attraction between a hydrogen atom and an electronegative atom, and a carboxyl bond is not a common term in biochemistry.

Correct Answer: A

Rationale: The correct answer is A: 'incomplete.' Proteins from plant sources like grains, nuts, and legumes are considered incomplete because they often lack one or more essential amino acids required by the body. Choice B, 'complete,' is incorrect because complete proteins contain all essential amino acids in adequate amounts. Choice C, 'indispensable,' is incorrect as it refers to essential amino acids rather than the classification of plant proteins. Choice D, 'dispensable,' is also incorrect as it implies that these proteins are not necessary, which is not the case.

Correct Answer: B

Rationale: Excessive intake of dietary protein can lead to impaired kidney function over time. Excessive protein consumption can put a strain on the kidneys as they work to eliminate the byproducts of protein metabolism. This can potentially lead to kidney damage. Choices A, C, and D are incorrect. Excessive protein intake is not directly linked to causing vitamin deficiencies, increasing weight loss, or decreasing the production of indispensable amino acids.

Correct Answer: B

Rationale: The correct answer is B: Intestinal mucosa. The intestinal mucosa has the highest rate of protein turnover due to its rapid cell renewal. The skin, muscle, and adipose tissue do not exhibit protein turnover rates as high as the intestinal mucosa. Skin cells turnover relatively slower compared to the rapid renewal of intestinal mucosa cells. Muscles have a moderate rate of protein turnover, while adipose tissue has a lower turnover rate compared to the other tissues mentioned.

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.