How is resistant starch digested in the colon?
- A. bacterial fermentation.
- B. pancreatic amylase.
- C. hydrochloric acid.
- D. villi and microvilli.
Correct Answer: A
Rationale: In the colon, resistant starch is digested by bacterial fermentation. The correct answer is A. During this process, short-chain fatty acids are produced. Pancreatic amylase, as mentioned in choice B, is responsible for breaking down starch in the small intestine, not in the colon. Choice C, hydrochloric acid, functions in the stomach to aid in the digestion of proteins, not starch. Villi and microvilli, as stated in choice D, are structures in the small intestine that absorb nutrients; they do not participate in the digestion of resistant starch in the colon.
You may also like to solve these questions
What is the mechanism that is essential for the absorption of monosaccharides?
- A. Phosphorylation
- B. Active transport
- C. Passive diffusion
- D. Facilitated diffusion
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.
What is the preferred fuel for the cells lining the colon?
- A. Short-chain fatty acids.
- B. Long-chain fatty acids.
- C. Amino acids.
- D. Glucose.
Correct Answer: A
Rationale: Short-chain fatty acids are the preferred fuel for the cells lining the colon. They provide energy and support gut health by serving as a fuel source for these cells. Long-chain fatty acids are not the preferred fuel for colon cells as they are harder to digest and absorb in this part of the digestive system. Amino acids are the building blocks of proteins and not the primary energy source for colon cells. Glucose is the main energy source for most cells in the body, but colon cells prefer short-chain fatty acids.
Which enzyme is produced by the parotid gland?
- A. Salivary amylase
- B. Sucrase
- C. Maltase
- D. Lactase
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.
During lactation, where is lactose synthesized in the body?
- A. Liver
- B. Breast
- C. Kidney
- D. Pancreas
Correct Answer: B
Rationale: The correct answer is B: Breast. Lactose is synthesized in the breast during lactation to produce breastmilk. The liver is responsible for various metabolic functions but does not synthesize lactose. The kidney's primary role is in filtering blood and regulating electrolytes, not lactose synthesis. The pancreas is involved in producing digestive enzymes and insulin, not lactose synthesis.
Carbohydrates are composed of a combination of carbon, hydrogen, and which other element?
- A. oxygen.
- B. nitrogen.
- C. water.
- D. glucose.
Correct Answer: A
Rationale: Carbohydrates are composed of carbon, hydrogen, and oxygen. These three elements combine to form the basic structure of carbohydrates. Oxygen is an essential element in carbohydrates, contributing to their chemical composition. Choice B (nitrogen) is incorrect as nitrogen is not a typical component of carbohydrates. Choice C (water) is incorrect as water is not an element but a compound composed of hydrogen and oxygen. Choice D (glucose) is incorrect as glucose is a specific type of sugar, not an element found in the composition of carbohydrates.