What differentiates one amino acid from another?

Correct Answer: C

Rationale: The side chain, also known as the R group, is what differentiates one amino acid from another. It imparts unique properties to each amino acid, thereby influencing their roles and functions in proteins. The amine group (Choice A) and the acid group (Choice B) are components of all amino acids and do not cause the differences among various amino acids. Choice D is incorrect as it suggests that none of the given options account for the differences, which is not true as the side chain does.

Correct Answer: D

Rationale: The correct answer is 'antioxidants and phytochemicals'. Antioxidants and phytochemicals help reduce oxidative damage in the body, contributing to healthy aging and a lower risk of chronic diseases. This is the same effect observed in animals when their energy intake is restricted. The other choices are incorrect as there is no direct evidence connecting reduced oxidative damage with diets high in fiber and carbohydrates, fatty acids and protein, or probiotics.

Correct Answer: C

Rationale: The side chain, also known as the R group, is what differentiates one amino acid from another. It imparts unique properties to each amino acid, thereby influencing their roles and functions in proteins. The amine group (Choice A) and the acid group (Choice B) are components of all amino acids and do not cause the differences among various amino acids. Choice D is incorrect as it suggests that none of the given options account for the differences, which is not true as the side chain does.

Correct Answer: D

Rationale: The correct answer is D: potato chips. Potato chips, especially when fried in hydrogenated oils, are a common source of trans fats, which are linked to an increased risk of coronary heart disease (CHD). Hot dogs (choice A) can also contain trans fats if made with processed meats and added fats. Whole milk (choice B) and fatty fish (choice C) do not typically contain trans fats, making them less likely sources compared to potato chips.

Correct Answer: A

Rationale: The correct answer is A: Obesity. Among older adults, obesity is the most common nutritional disorder. This is often attributed to reduced physical activity levels and changes in metabolism that occur with aging. Choice B (Underweight) is less common among older adults as compared to obesity. While choices C (Vitamin deficiency) and D (Dehydration) are important nutritional issues, they are generally not as prevalent as obesity in the older adult population.

Correct Answer: D

Rationale: The correct answer is D: vitamins A, E, K, and D. Fat-soluble vitamins are absorbed along with fats in the diet and can be stored in the body's fatty tissue. Vitamins B and C are water-soluble vitamins and are not stored in the body; any excess amounts are usually excreted in the urine. Therefore, choices A, B, and C are incorrect.

Correct Answer: B

Rationale: The correct answer is folate. Folate, also known as Vitamin B9, is vital for the prevention of neural tube defects in the developing fetus. It is primarily responsible for the creation and repair of DNA, which is essential during rapid growth stages such as pregnancy. While nutrients like calcium, vitamin A, and choline are important for pregnancy, they are not as directly linked to preventing neural tube defects as folate. Calcium is crucial for the baby's bone and teeth development. Vitamin A is essential for vision, immune function, and cellular growth. Choline supports brain development and neural functioning. However, none of these nutrients have the same direct impact on preventing neural tube defects as folate.

Correct Answer: D

Rationale: The correct answer is 'D. triglyceride.' Triglycerides are composed of one glycerol molecule and three fatty acids, making them the primary form of stored fat in the body. Cholesterol (A) is a different type of lipid, phospholipids (B) have two fatty acids, and 'saturated' (C) refers to the structure of fatty acids, not a specific lipid containing 3 fatty acids.

Correct Answer: D

Rationale: The primary purpose of dietary fiber in the diet is to reduce cholesterol levels. While it does aid in digestion by promoting regular bowel movements, its main role is in lowering cholesterol. Choice A is partially correct but not the primary purpose. Choice B is incorrect as fiber is not a direct source of energy. Choice C is also incorrect as the primary role of fiber is not in the absorption of vitamins.