What enzyme breaks down proteins into peptides in structure W?

Correct Answer: C

Rationale: The correct answer is C: pepsin. Pepsin is an enzyme produced in the stomach that breaks down proteins into peptides. It functions in an acidic environment, which is characteristic of the stomach. Amylase (A) breaks down carbohydrates, lipase (B) breaks down fats, and trypsin (D) breaks down proteins in the small intestine, not in structure W.

Correct Answer: C

Rationale: Rationale: Insulin facilitates the uptake of glucose from the bloodstream into body cells. When insulin is injected into a healthy person, it enhances glucose absorption by body cells, leading to an increase in glucose concentration within the cells. This process helps regulate blood glucose levels by promoting glucose utilization for energy production and storage. Therefore, choice C is correct. Summary: A: Blood glucose levels would not increase as insulin promotes glucose uptake into cells. B: The liver would not convert glycogen into glucose as a response to insulin injection. D: The cell membrane would not become less permeable to glucose; insulin increases glucose uptake by enhancing membrane transport proteins.

Correct Answer: B

Rationale: The correct answer is B: starch. Salivary glands release amylase to break down starch into maltose in the mouth. Pancreatic amylase continues starch digestion in the small intestine. Fat is broken down by lipase, not secretions from salivary glands or pancreas. Protein is digested by pepsin in the stomach and proteases in the small intestine. Maltose is a product of starch digestion, not the substance digested directly by salivary glands and pancreas.

Correct Answer: C

Rationale: The correct answer is C: mouth, stomach, small intestine. Digestive enzymes are secreted in these specific parts to aid in the breakdown of food. In the mouth, salivary glands produce amylase to start breaking down carbohydrates. In the stomach, gastric glands secrete pepsin to break down proteins. In the small intestine, the pancreas secretes various enzymes such as lipase, protease, and amylase to further break down proteins, fats, and carbohydrates. Choices A, B, and D are incorrect because they do not include all three key locations where digestive enzymes are secreted.

Correct Answer: B

Rationale: The correct answer is B: gall bladder. Bile, which emulsifies fats in the small intestines, is produced by the liver and stored in the gall bladder. When the body detects the presence of fats in the small intestines, the gall bladder releases bile into the small intestines to aid in the emulsification process. The stomach (A) is responsible for the initial digestion of food and does not release bile. Villi (C) are tiny finger-like projections in the small intestines that help with nutrient absorption, not bile release. Lacteals (D) are lymphatic vessels in the small intestines that absorb fats and fat-soluble vitamins, but they do not release bile.