Which enzyme is produced by the parotid gland?

Correct Answer: A

Rationale: The correct answer is A, Salivary amylase. Salivary amylase is an enzyme produced by the parotid gland that initiates starch digestion in the mouth. It helps break down starch into maltose, a simpler sugar. Choices B, C, and D are incorrect because sucrase, maltase, and lactase are enzymes involved in the digestion of disaccharides like sucrose, maltose, and lactose, respectively, in the small intestine, not in the saliva.

Correct Answer: A

Rationale: Protein catabolism increases in conditions like severe burns because the body breaks down muscle protein to provide energy for healing. Severe obesity does not necessarily increase protein catabolism; instead, it is more related to excessive fat accumulation. Hypothyroidism may lead to a decrease in metabolic rate but does not directly increase protein catabolism. Food allergies trigger an immune response to specific foods but do not directly impact protein catabolism.

Correct Answer: B

Rationale: Active transport is the mechanism essential for the absorption of monosaccharides in the intestine. This process requires energy to move molecules against their concentration gradient, allowing for the absorption of monosaccharides efficiently. Phosphorylation, the process of adding a phosphate group to a molecule, is not directly involved in the absorption of monosaccharides. Passive diffusion, a process that does not require energy, is not the primary mechanism for absorbing monosaccharides due to their large size. Facilitated diffusion, a type of passive transport that involves carrier proteins, is not the primary mechanism for monosaccharide absorption, as monosaccharides require active transport for efficient absorption.

Correct Answer: C

Rationale: The correct answer is C, intramural nerve plexus. The intramural nerve plexus is the interrelated network of nerves within the gastrointestinal wall that regulates its muscular action. The gastric nerve plexus (choice A) specifically pertains to the network of nerves in the stomach, not the entire gastrointestinal wall. The biliary nerve plexus (choice B) is associated with nerve supply in the liver, gallbladder, and bile ducts, not the gastrointestinal wall. The intestinal nerve plexus (choice D) is a general term that may refer to various nerve networks within the intestines but does not specifically address the entire gastrointestinal wall.

Correct Answer: C

Rationale: The correct answer is C because essential fatty acids are not manufactured by the body and must be obtained through the diet. Choice A is incorrect because essential fatty acids can come from plant sources as well. Choice B is incorrect as essential fatty acids are primarily derived from plant sources. Choice D is incorrect because essential fatty acids cannot be produced by the body. Therefore, the only accurate statement is that essential fatty acids are not manufactured by the body.