What is the major diet-derived antioxidant found in cell membranes?

Correct Answer: C

Rationale: The correct answer is vitamin E. Vitamin E is the major antioxidant found in cell membranes, where it plays a crucial role in protecting them from oxidative damage. Although B12, beta-carotene, and vitamin A are important nutrients with specific functions in the body, they are not the primary antioxidants found in cell membranes. Vitamin E specifically localizes in cell membranes to neutralize free radicals and prevent lipid peroxidation, making it an essential antioxidant for cellular health.

Correct Answer: B

Rationale: The correct answer is B: Avoid gluten. Patients with celiac disease have an immune reaction to gluten, a protein found in wheat, barley, and rye. Therefore, it is crucial for individuals with celiac disease to avoid gluten-containing products. Increasing protein intake (Choice A) is not specifically necessary for celiac disease management. Increasing dairy intake (Choice C) is unrelated to the dietary requirements of individuals with celiac disease. Avoiding lactose (Choice D) is relevant for individuals with lactose intolerance, not celiac disease. Therefore, the only necessary modification for a patient with celiac disease is to avoid gluten.

Correct Answer: C

Rationale: The correct answer is Vitamin D. Vitamin D is synthesized in the skin when it is exposed to sunlight. This process allows the body to produce Vitamin D naturally. Vitamin A (Choice A) is found in foods like liver and carrots and is not primarily obtained from sunlight. Vitamin C (Choice B) is commonly found in fruits and vegetables. Vitamin E (Choice D) is present in foods like nuts and seeds and is not primarily obtained from sunlight.

Correct Answer: D

Rationale: Proteins, carbohydrates, and fats are macronutrients that provide energy in the form of calories when consumed and metabolized by the body. Each gram of protein or carbohydrate provides about 4 calories, and each gram of fat provides about 9 calories. On the other hand, vitamins do not provide energy or calories. They are micronutrients that are essential for various biochemical and physiological processes in the body, including the metabolism of macronutrients. However, they do not contribute directly to the energy supply. Therefore, the correct answer is 'D: Vitamins'. Choices A, B, and C (Proteins, Carbohydrates, and Fats) are incorrect because they are macronutrients that do provide energy/calories when metabolized.

Correct Answer: B

Rationale: Energy drinks are known for causing a variety of health issues, including nervousness, seizures, and an increased risk of dental caries due to their high sugar content. However, they do not cause bradycardia, which is a slow heart rate. Instead, energy drinks are associated with causing an increased or rapid heart rate, known as tachycardia. Therefore, out of the listed options, bradycardia is the condition not caused by energy drinks.