In a demonstration, 10 grams of raw meat were suspended in an enzyme solution. After several hours the meat was weighed and was found to have a mass of 3 grams. The solution most likely contained

Correct Answer: B

Rationale: The correct answer is B: pepsin. Pepsin is a digestive enzyme that breaks down proteins into smaller peptides. In this demonstration, the decrease in mass of the meat from 10g to 3g suggests protein digestion occurred. Bile (A) emulsifies fats, maltose (C) breaks down carbohydrates, and amylase (D) also breaks down carbohydrates, so they wouldn't cause the observed mass change.

Correct Answer: C

Rationale: Sure. Secretin is the correct answer as it specifically stimulates the release of pancreatic juice. Secretin is released from the duodenum in response to the acidic chyme entering from the stomach. It acts on the pancreas to increase the secretion of bicarbonate-rich pancreatic juice, which helps neutralize the acidic chyme. Insulin (choice A) regulates blood sugar levels, gastrin (choice B) stimulates gastric acid secretion, and glucagon (choice D) increases blood glucose levels. These hormones do not directly stimulate the release of pancreatic juice.

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.