Question 1

Which of the following best describes the process illustrated in the first image (showing a dipeptide being split into alanine and glycine)?

Accepted Answer

Hydrolysis, where a water molecule is used to break a peptide bond between amino acids.

Question 2

A patient accidentally ingests elemental mercury. Based on the absorption mechanisms in the alimentary canal, what is the most likely outcome?

Accepted Answer

Mercury will mostly pass through the alimentary canal unabsorbed because there is no transport protein for it.

Question 3

Which enzyme is responsible for the initial chemical digestion of carbohydrates in the mouth?

Accepted Answer

Salivary amylase

Question 4

Why does the absorption of glucose and galactose require energy input in the small intestine?

Accepted Answer

Because they are transported against their concentration gradients via secondary active transport using the Na+/glucose cotransporter.

Question 5

Which of the following statements about fructose absorption is correct?

Accepted Answer

Fructose is absorbed by facilitated diffusion, which requires a concentration gradient.

Question 6

A patient with lactose intolerance consumes a large amount of milk. Which of the following best explains their symptoms of abdominal cramping and diarrhea?

Accepted Answer

Lactose remains undigested, acts as an osmotic particle, and draws water into the feces.

Question 7

Which enzyme is responsible for activating other pancreatic proteases in the small intestine?

Accepted Answer

Trypsin

Question 8

What is the primary mechanism by which amino acids are absorbed across the apical membrane of enterocytes?

Accepted Answer

Secondary active transport using a Na+ gradient

Question 9

Which of the following best describes the role of bile salts in lipid digestion?

Accepted Answer

They emulsify large lipid globules into smaller droplets, increasing surface area for enzyme action.

Question 10

After absorption, how are most dietary lipids transported from the small intestine to the bloodstream?

Accepted Answer

As chylomicrons through lymphatic vessels, eventually entering the blood via the thoracic duct

Question 11

Which of the following vitamins requires intrinsic factor for absorption in the ileum?

Accepted Answer

Vitamin B12

Question 12

A patient has had their stomach surgically removed. Which nutrient deficiency are they most at risk for, and why?

Accepted Answer

Vitamin B12, because intrinsic factor is no longer produced.

Question 13

Which of the following best explains why water absorption in the small intestine occurs?

Accepted Answer

Water moves by osmosis due to a concentration gradient created by solute absorption.

Question 14

Which of the following is a correct sequence for the chemical digestion of proteins?

Accepted Answer

Pepsin in the stomach → pancreatic enzymes in the small intestine → brush border enzymes

Question 15

Which of the following mechanisms is responsible for the absorption of most water-soluble vitamins in the small intestine?

Accepted Answer

Simple diffusion through enterocyte plasma membranes

Question 16

Which of the following statements about the absorption of electrolytes is correct?

Accepted Answer

Sodium ion absorption is coupled with the cotransport of monosaccharides and amino acids.

Question 17

Which of the following best explains why fat-soluble vitamins are absorbed differently from water-soluble vitamins?

Accepted Answer

Fat-soluble vitamins are packaged into micelles with lipids and absorbed with them.

Question 18

Which of the following is a direct result of the Na+/K+ pump activity in enterocytes during carbohydrate absorption?

Accepted Answer

A sodium ion gradient is established, which drives the secondary active transport of glucose and galactose.

Question 19

Which of the following is a consequence of a lack of brush border enzymes in the small intestine?

Accepted Answer

Disaccharides and oligosaccharides will not be fully digested into monosaccharides.

Question 20

Which of the following best describes the fate of chylomicrons after they are released from enterocytes?

Accepted Answer

They enter lacteals and travel through the lymphatic system before entering the bloodstream.

Nutrient Digestion and Absorption: Mechanisms and Clinical Insights 22.7

Study Guide - Practice Questions

Study Guide - Flashcards