Question 1

Bile salts are
A) amphipathic.
B) completely hydrophilic.
C) completely hydrophobic.

Accepted Answer

Bile salts are amphipathic, meaning they have both hydrophilic (water-attracting) and hydrophobic (water-repelling) properties, which allows them to emulsify fats in the digestive system.

Question 2

Carboxypeptidase is an enzyme that helps digest
A) amino acids within the stomach.
B) complex carbohydrates within the small intestine.
C) peptides within the small intestine.
D) disaccharides within the duodenum.
E) starch within the stomach.

Accepted Answer

Carboxypeptidase is an enzyme that breaks down peptides into amino acids in the small intestine.

Question 3

As a protein is broken down into smaller and smaller fragments, each fragment ultimately requires splitting of the last peptide bond within it. The breaking of the bond between those last two amino acids is catalyzed by the enzyme
A) pepsin.
B) chymotrypsin.
C) dipeptidase.
D) trypsin.
E) glucoamylase.

Accepted Answer

Dipeptidase is the enzyme that specifically catalyzes the hydrolysis of dipeptides into their constituent amino acids by breaking the last peptide bond.

Question 4

Within intestinal epithelial cells, lipids are wrapped in a protein coat to form ________, which will be packaged into secretory vesicles at the Golgi apparatus.

Accepted Answer

The answer of Within intestinal epithelial cells, lipids are wrapped...

Question 5

Which is an accurate description of glucose and sucrose?
A) Glucose is a monosaccharide, sucrose is a polysaccharide, both molecules are starches.
B) Glucose is a monosaccharide, sucrose is a disaccharide, both molecules are carbohydrates.
C) Glucose is a disaccharide, sucrose is a monosaccharide, both molecules are lipids.
D) Glucose is a disaccharide, sucrose is a glycolipid, both molecules are essential nutrients.
E) Glucose is a monoamine, sucrose is a dipeptide, both molecules are acidic.

Accepted Answer

Glucose is a monosaccharide, which is the simplest form of sugar, while sucrose is a disaccharide composed of glucose and fructose. Both are carbohydrates.

Question 6

Pepsinogen is an
A) active enzyme that is released in the small intestine and digests carbohydrates.
B) inactive precursor to the enzyme pepsin that digests proteins in the stomach.
C) active enzyme that digests proteins within the small intestine.
D) inactive precursor to a nonspecific enzyme that is synthesized in the pancreas and released in the small intestine.

Accepted Answer

Pepsinogen is an inactive precursor (zymogen) that is converted into the active enzyme pepsin in the stomach, where it digests proteins.

Question 7

The enzyme pepsin becomes active when pH is
A) high.
B) low.

Accepted Answer

Pepsin is a digestive enzyme that becomes active in the acidic environment of the stomach, which has a low pH.

Question 8

Chief cells store and release an inactive precursor of a proteolytic enzyme (rather than the active form) to avoid destroying proteins within themselves.

Accepted Answer

Chief cells release pepsinogen, an inactive precursor, which is converted to pepsin in the acidic environment of the stomach to prevent autodigestion of the cells themselves.

Question 9

Proteolytic enzymes secreted from the pancreas are activated
A) once they reach the pancreatic duct.
B) within the lumen of the small intestine.
C) in secretory vesicles within pancreatic secretory cells.
D) once they reach the large intestine.

Accepted Answer

Proteolytic enzymes from the pancreas are secreted in an inactive form and are activated in the lumen of the small intestine by enzymes such as enterokinase.

Question 10

Amylase from saliva digests
A) lipids.
B) protein.
C) glucose.
D) starch.

Accepted Answer

Amylase is an enzyme found in saliva that breaks down starch into simpler sugars.

Question 11

Digestion of carbohydrates within the small intestine involves enzymes that come from the
A: mouth.
B: stomach.
C: pancreas.
D: lining of the small intestine.
A) a, b
B) b, c
C) c, d
D) a, d
E) a, b, c, d

Accepted Answer

The pancreas produces enzymes like amylase that help digest carbohydrates, and the lining of the small intestine produces enzymes like maltase, sucrase, and lactase for further carbohydrate digestion.

Question 12

A complex carbohydrate that consists of several repeating units of simple sugars is referred to as a ________.

Accepted Answer

The answer of A complex carbohydrate that consists of several...

Question 13

Salivary amylase is activated once it enters the acidic environment of the stomach.

Accepted Answer

Salivary amylase is inactivated in the acidic environment of the stomach, as it requires a neutral to slightly alkaline pH to function effectively.

Question 14

Digestion of proteins is initiated by the enzyme
A) amylase.
B) hydrochloric acid.
C) aminopeptidase.
D) pepsin.
E) CCK.

Accepted Answer

Pepsin is the enzyme responsible for initiating the digestion of proteins in the stomach. It is activated from its precursor, pepsinogen, by the acidic environment provided by hydrochloric acid.

Question 15

Maltase is a brush border enzyme of the small intestine that digests the sugar maltose.

Accepted Answer

Maltase is an enzyme located in the brush border of the small intestine, and it specifically breaks down maltose into two glucose molecules.

Question 16

Once micelles enter intestinal epithelial cells, fatty acids and monoglycerides combine to form triglycerides.

Accepted Answer

Inside intestinal epithelial cells, fatty acids and monoglycerides are re-esterified to form triglycerides, which are then packaged into chylomicrons for transport.

Question 17

The process by which bile breaks up large fat droplets into smaller ones is called ________.

Accepted Answer

The answer of The process by which bile breaks up...

Question 18

Bile catalyzes the breakdown of triglyceride into a monoglyceride and two free fatty acids.

Accepted Answer

Bile does not catalyze the breakdown of triglycerides; it emulsifies fats, increasing their surface area for lipase enzymes to act on them.

Question 19

Lactose intolerant individuals cannot digest the ________ lactose because they lack the enzyme ________.
A) polysaccharide; maltase
B) disaccharide; lactase
C) monosaccharide; dextrolactase
D) lipid; pancreatic lipase
E) fatty acid; sucrolactase

Accepted Answer

Lactose intolerant individuals cannot digest the disaccharide lactose because they lack the enzyme lactase.

Question 20

Nucleic acids are digested within the
A) mouth.
B) stomach.
C) small intestine.
D) pancreas.
E) large intestine.

Accepted Answer

Nucleic acids are primarily digested in the small intestine where enzymes like nucleases break them down into nucleotides.

Quiz 26: Digestive System

Bile salts are

Carboxypeptidase is an enzyme that helps digest

As a protein is broken down into smaller and smaller fragments, each fragment ultimately requires splitting of the last peptide bond within it. The breaking of the bond between those last two amino acids is catalyzed by the enzyme

Within intestinal epithelial cells, lipids are wrapped in a protein coat to form ________, which will be packaged into secretory vesicles at the Golgi apparatus.

Which is an accurate description of glucose and sucrose?

Pepsinogen is an

The enzyme pepsin becomes active when pH is

Chief cells store and release an inactive precursor of a proteolytic enzyme (rather than the active form) to avoid destroying proteins within themselves.

Proteolytic enzymes secreted from the pancreas are activated

Amylase from saliva digests

Digestion of carbohydrates within the small intestine involves enzymes that come from the A: mouth. B: stomach. C: pancreas. D: lining of the small intestine.

A complex carbohydrate that consists of several repeating units of simple sugars is referred to as a ________.

Salivary amylase is activated once it enters the acidic environment of the stomach.

Digestion of proteins is initiated by the enzyme

Maltase is a brush border enzyme of the small intestine that digests the sugar maltose.

Once micelles enter intestinal epithelial cells, fatty acids and monoglycerides combine to form triglycerides.

The process by which bile breaks up large fat droplets into smaller ones is called ________.

Bile catalyzes the breakdown of triglyceride into a monoglyceride and two free fatty acids.

Lactose intolerant individuals cannot digest the lactose because they lack the enzyme .

Nucleic acids are digested within the