Which of these enzymes is responsible for digesting proteins?

Correct Answer: C

Rationale: The correct answer is C: trypsin. Trypsin is responsible for digesting proteins as it specifically breaks down proteins into smaller peptides. Amylase (A) digests carbohydrates, lipase (B) breaks down fats, and sucrase (D) digests sucrose, a type of sugar. Trypsin is produced by the pancreas and plays a crucial role in protein digestion in the small intestine. Its specificity for proteins makes it the correct enzyme for this function.

Correct Answer: C

Rationale: The correct answer is C: absorption of nutrients. The small intestine is responsible for absorbing nutrients from digested food into the bloodstream for distribution to the body's cells. It has specialized structures like villi and microvilli to maximize absorption surface area. Choice A is incorrect because while the small intestine does play a role in digesting fats, it is not its primary function. Choice B is incorrect because the digestion of carbohydrates primarily occurs in the mouth and stomach. Choice D is incorrect as the small intestine does not store bile, but rather receives it from the liver and gallbladder to aid in digestion.

Correct Answer: B

Rationale: The correct answer is B: Stomach. Protein digestion begins in the stomach where the enzyme pepsin is secreted. Pepsin breaks down proteins into smaller peptides. This process is aided by the acidic environment of the stomach. In contrast, the mouth primarily starts the digestion of carbohydrates through the enzyme salivary amylase. The small intestine is where further breakdown and absorption of nutrients occur, not the initial digestion of proteins. The large intestine is mainly responsible for absorbing water and electrolytes, not digestion.

Correct Answer: A

Rationale: The correct answer is A: It gives bile its color. Bilirubin is a pigment produced from the breakdown of hemoglobin in the liver, giving bile its characteristic yellow-green color. This is important for bile to aid in the emulsification and digestion of fats. Choices B and D are incorrect as stercobilinogen is produced from bilirubin in the intestine, contributing to stool color, not bile color. Choice C is incorrect as bile salts, not bilirubin, facilitate the absorption of lipids in the small intestine.

Correct Answer: D

Rationale: The correct answer is D because parasympathetic stimulation causes the contraction of the gall bladder. This is due to the release of acetylcholine which stimulates the gall bladder to contract and release bile into the duodenum to aid in digestion. Choices A, B, and C are incorrect as parasympathetic stimulation does not cause constriction of the pylorus, contraction of the internal anal sphincter, or contraction of the external anal sphincter.