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Lesson Worksheet: The Digestive Process Biology

In this worksheet, we will practice describing the processes of buccal, gastric, and intestinal digestion in the human body.

Q1:

Which of the following is not an adaptation of the stomach for digestion?

  • AThe stomach has a low pH that is optimum for the activation of pepsin.
  • BThe epithelial cells of the stomach produce a mucus lining that acts as a protective layer.
  • CThe body of the stomach is composed of muscle that allows the stomach to mechanically churn food.
  • DThe stomach produces hydrochloric acid that helps break down food and pathogens.
  • EThe stomach produces and stores bile to aid the breakdown of fats.

Q2:

The table below shows the composition of the pancreatic juice.

SubstanceSodium bicarbonate AmylaseTrypsinogenLipase
FunctionNeutralizes the HCl released by the stomach to keep the duodenum slightly alkalineIs activated by the enzyme enterokinase to form trypsin, a protease enzyme

What is the function of amylase?

  • ATo activate the enzyme pepsin from pepsinogen
  • BTo catalyze the hydrolysis of proteins into amino acids
  • CTo catalyze the hydrolysis of carbohydrates, glycogen, and starch
  • DTo catalyze the hydrolysis of fats into glycerol and fatty acid molecules

What is the function of lipase?

  • ATo activate the enzyme pepsin from pepsinogen
  • BTo catalyze the hydrolysis of carbohydrates, glycogen, and starch
  • CTo catalyze the hydrolysis of fats into glycerol and fatty acid molecules
  • DTo catalyze the hydrolysis of proteins into amino acids

Q3:

Which of the following is the correct order of the different stages of digestion?

  • ABuccal intestinal gastric
  • BBuccal gastric intestinal
  • CGastric buccal intestinal
  • DIntestinal gastric buccal

Q4:

Which class of enzymes present in the intestinal juice will hydrolyze the peptide bonds within a polypeptide chain?

  • ALipases
  • BPeptidases
  • CCarbohydrases
  • DAmylases

Q5:

What is the main function of the digestive system?

  • ARegulating cellular metabolism and respiration
  • BSynthesizing large molecules from smaller ones
  • CBreaking down large, insoluble molecules into smaller, soluble ones
  • DMaintaining a constant internal environment
  • ECollecting and processing information from external and internal stimuli

Q6:

The pH of the digestive tract changes between organs. What is the approximate pH range of the following organs?

The stomach

  • A14 to 14.5
  • B7 to 8
  • C10 to 12
  • D1.5 to 3

The small intestine

  • A5 to 9.5
  • B7 to 8.5
  • C1.5 to 3
  • D10 to 12

Q7:

How is food transported from the mouth to the stomach?

  • ABy absorption into the bloodstream
  • BBy the diffusion of substances down their concentration gradient
  • CBy a series of muscular contractions in the esophagus
  • DBy being pulled down the trachea

Q8:

Pepsinogen is secreted by the cells that line the stomach. What is pepsinogen converted into?

  • ACollagen
  • BPepsin
  • CPolypeptides
  • DTrypsin
  • ECarcinogen

Q9:

What is the main function of pepsin in gastric digestion?

  • ATo initiate peristalsis in the esophagus
  • BTo break down proteins into smaller fragments of polypeptides
  • CTo break down polysaccharides into small sugars
  • DTo emulsify fats

Q10:

The stomach itself is made up of proteins; why does the pepsin released by the stomach not end up digesting the stomach?

  • AThe inside of the stomach is lined with villi, which absorb the pepsin.
  • BThe hydrochloric acid released by the stomach deactivates pepsin if it touches the stomach lining.
  • CThe epithelial cells of the stomach secrete a protective mucus layer.
  • DThe stomach is continually churning and moving to prevent the pepsin from interacting with the stomach muscle.

This lesson includes 28 additional questions for subscribers.

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