A dietitian tells you that you are not consuming enough calories. Which of the following nutrients could you add to your diet to increase your energy intake?

Correct Answer: C

Rationale: Corrected Rationale: Protein provides 4 kcal per gram, making it a good source of energy to increase caloric intake. While fiber and water are important for other aspects of health, they do not provide energy like protein does. Vitamins are essential for various bodily functions but do not contribute directly to caloric intake.

Correct Answer: D

Rationale: Villi and microvilli in the GI tract serve to increase the surface area of the small intestine, aiding in the absorption of nutrients into the bloodstream. Choices A, B, and C are incorrect as villi and microvilli are primarily involved in enhancing absorption, not in producing bile, killing bacteria, or producing vitamin K.

Correct Answer: A

Rationale: The statement is TRUE. Sickle cell disease is caused by a genetic mutation in the hemoglobin gene, leading to an abnormal amino acid sequence. This results in the production of abnormal hemoglobin molecules, causing red blood cells to become sickle-shaped. This inherited condition is a classic example of a genetic error affecting the amino acid sequence, making choice A the correct answer. Choices B, C, and D are incorrect as they do not accurately reflect the nature of sickle cell disease.

Correct Answer: B

Rationale: The correct answer is B: Emulsify fats in the small intestine. Bile emulsifies fats in the small intestine, breaking them down into smaller droplets that can be more easily digested by enzymes like lipase. Choice A is incorrect as fats are not digested in the stomach but rather in the small intestine. Choice C is incorrect as fats are transported through the lymphatic system instead of the circulatory system. Choice D is incorrect as fats are broken down into smaller components through emulsification, not splitting.

Correct Answer: C

Rationale: The correct answer is C: bicarbonate ions. Bicarbonate ions, secreted by the pancreas, neutralize the acidic chyme entering the small intestine from the stomach, creating a more suitable environment for digestive enzymes. Saliva (choice A) helps in the initial breakdown of food in the mouth, not in neutralizing stomach acid. Gastric mucus (choice B) protects the stomach lining from the acidic environment but does not neutralize the acid in the small intestine. Enzymes (choice D) facilitate chemical reactions in digestion but do not neutralize stomach acid.