What enzyme is responsible for digesting proteins?

Correct Answer: C

Rationale: The correct answer is C: pepsin. Pepsin is an enzyme produced in the stomach that specifically breaks down proteins into peptides. Amylase (A) digests carbohydrates, lipase (B) digests fats, and sucrase (D) digests sucrose. Pepsin is the only enzyme among the choices that is responsible for digesting proteins, making it the correct answer.

Correct Answer: D

Rationale: The correct answer is D, Vitamin B12. The jejunum is not the main site for absorption of Vitamin B12; instead, it is absorbed in the terminal ileum. Glucose, amino acids, and fatty acids are primarily absorbed in the jejunum. Absorption of Vitamin B12 occurs in the ileum where it binds to intrinsic factor secreted by the stomach. Therefore, the jejunum is not the main site for absorption of Vitamin B12, making it the correct answer. Choices A, B, and C are incorrect because the jejunum is indeed the main site for absorption of glucose, amino acids, and fatty acids, respectively.

Correct Answer: C

Rationale: Rationale: The stomach primarily functions in digestion and does not have significant absorption capabilities. Glucose is absorbed in the small intestine through specialized transport mechanisms. Choices A (Ca) and D (aromatic amino acids) are primarily absorbed in the small intestine as well. Alcohol is absorbed in the stomach to a small extent, but the majority is absorbed in the small intestine. Therefore, the correct answer is C (Glucose) as it is primarily absorbed in the small intestine, not the stomach.

Correct Answer: C

Rationale: Congenital lesions causing vomiting in the first three days include pyloric stenosis and intestinal atresia. Pyloric stenosis typically presents with non-bilious projectile vomiting in the first few weeks of life, while intestinal atresia presents with bilious vomiting shortly after birth. Therefore, the correct answer is C, as both conditions can manifest with vomiting within the first three days of life. Choice A and B alone are incorrect because they each only represent one of the conditions, and choice D is incorrect as both conditions can present with vomiting in the specified time frame.

Correct Answer: D

Rationale: The correct answer is D: appendix. Carcinoid tumors in the appendix are considered the most benign due to their slow growth rate and low metastatic potential. The appendix is a small organ with limited blood supply, which restricts tumor growth and dissemination. Other choices (A: stomach, B: small intestine, C: rectum) have higher malignant potential due to larger size, increased blood supply, and higher likelihood of metastasis. Therefore, the appendix is the most benign location for carcinoid tumors.