$$\text{Pepsinogen} + \text{HCl} \rightarrow \text{Pepsin}$$

Question 1

Which of the following best describes the role of salivary amylase in the oral cavity during digestion?

Accepted Answer

It initiates the breakdown of starches into simpler sugars.

Question 2

Why is pepsinogen secreted in an inactive form by chief cells in the stomach?

Accepted Answer

To avoid the enzyme breaking down the cells and tissues of the stomach itself.

Question 3

Which combination of secretions is necessary to activate pepsin in the stomach?

Accepted Answer

Hydrochloric acid and pepsinogen

Question 4

A patient has a genetic disorder that prevents the secretion of bicarbonate from the pancreas. Which of the following is the most likely consequence?

Accepted Answer

The small intestine will be damaged by acidic chyme from the stomach.

Question 5

Which of the following best explains why the small intestine has villi and microvilli?

Accepted Answer

To increase the surface area for nutrient absorption.

Question 6

If a person’s parietal cells are destroyed, which of the following would most likely occur?

Accepted Answer

The person would have difficulty producing hydrochloric acid, impairing protein digestion.

Question 7

Which of the following equations best represents the conversion of pepsinogen to pepsin in the stomach?

Accepted Answer

$$	ext{Pepsinogen} + 	ext{HCl} ightarrow 	ext{Pepsin}$$

Question 8

A person eats a meal high in carbohydrates. Which of the following best describes the sequence of events for blood glucose regulation after eating?

Accepted Answer

Blood glucose increases, pancreas releases insulin, glucose is stored as glycogen.

Question 9

Which of the following is a function of the microbiome in the large intestine?

Accepted Answer

Breaking down cellulose and producing volatile fatty acids.

Question 10

If antibiotics kill the microbiome in the large intestine, which of the following is a likely result?

Accepted Answer

Decreased production of volatile fatty acids such as acetic, propionic, and butyric acid.

Question 11

Which of the following best describes the mechanical regulation of digestion?

Accepted Answer

The sensation of 'fullness' that signals to stop eating.

Question 12

A person is unable to produce mucus in their stomach. Which of the following is the most likely consequence?

Accepted Answer

Their stomach lining will be damaged by hydrochloric acid.

Question 13

Which of the following best explains why the pancreas releases glucagon?

Accepted Answer

To increase blood glucose levels when they are low by stimulating glycogen breakdown in the liver.

Question 14

Which of the following is a correct sequence for the digestion and absorption of fats?

Accepted Answer

Emulsification by bile in the small intestine, digestion by pancreatic lipase, absorption by villi.

Question 15

Which of the following best describes the function of chief cells in the stomach?

Accepted Answer

They secrete pepsinogen, the inactive precursor of pepsin.

Question 16

A person has a mutation that prevents the absorption of nutrients in the small intestine. Which of the following structures is most likely defective?

Accepted Answer

Villi and microvilli

Question 17

Which of the following best explains the role of bile in digestion?

Accepted Answer

It emulsifies fats, increasing their surface area for enzyme action.

Question 18

Which of the following equations best represents the regulation of blood glucose after eating a meal?

Accepted Answer

$$	ext{Glucose}_{	ext{blood}} \uparrow \Rightarrow 	ext{Pancreas releases insulin} \Rightarrow 	ext{Glucose stored as glycogen}$$

Question 19

Which of the following is a direct result of the absorption of volatile fatty acids (VFAs) produced by the microbiome in the large intestine?

Accepted Answer

Energy production for the host organism.

Question 20

A person is unable to produce sufficient insulin. Which of the following is the most likely physiological effect?

Accepted Answer

Blood glucose levels will remain elevated after eating.

Digestive System: Mechanisms and Regulation in General Biology

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