TOPIC 6 .1 Digestion Study Guide –
Instructions: Read pages 151 to 157 in your biology textbook. Then define the below vocabulary words
and address the below assessment statements.
Vocabulary words:
Enzyme
Amylase
Protease
Lipase
Stomach
Small intestine
Large intestine
Absorption
Assimilation
Villus
Assessment Statements
6.1.1
6.1.2
6.1.3
6.1.4
6.1.5
6.1.6
6.1.7
Explain why digestion of large food molecules is essential
Explain the need for enzymes in digestions
State the source, substrate, products and optimum pH conditions for one amylase, one protease
and one lipase
Draw and Label a diagram of the digestive system. This diagram should include the following
structures and clearly show the interconnections between these structures:
o Mouth
o Small
o Anus
o Esophagus
intestines
o Liver,
o Stomach
o Large
o Pancreas
intestines
o Gall bladder
Outline the function of the stomach, small intestine and large intestine
Distinguish between absorption and assimilation
Explain how the structure of the vıllus as related to the role an absorption and transport of the
products of digestion
Practice Questions (optional)
1. Define the following terms, giving an example of each.
Macromolecule
Ingestion
Digestion
Absorption
Assimilation
Excretion
Egestion
Enzyme
Substrate
Optimum pH
Lipase
“large molecules made up of smaller organic molecules. There are four
classes of macromolecules: carbohydrates, lipids, proteins and nucleic
acids” (1)
Protease
Amylase
2. Explain the need for digestion of large food molecules. (3 marks)
3. State the name of the type of reaction which uses water to break down a
macromolecule.
o
4. Explain the need for enzymes in digestion of large food molecules. (5marks)
5. Review: Explain three factors that affect the rate of enzyme activity. (8 marks)
6. State the source, substrate, products, and optimum pH for the following types of enzymes:
Carbohydrase (amylase)
Lipase
Protease
Substrate
Carbohydrates
Lipids/ fats
Example of
enzyme
trypsin
Product(s)
Source of
enzyme
Proteins
pancreas
Optimum
pH
7. Label and state the function of the structures of the digestive system below:
Name
Function
Salivary glands
Secrete saliva, includes amylase to being digestion of
starch.
a.
b.
c.
d.
e.
f.
g.
Small intestine
(duodenum)
h.
i.
j.
k
.
8. Outline the functions of the stomach and small intestine.
Stomach
Acid
Mechanical Digestion
Enzyme
Small intestine
Neutralisation of
chyme
Enzymes
Duodenum
Ileum
Peristalsis
9. The small intestine is made up of many finger-like projections called villi.
a. Distinguish between absorption and assimilation.
b. Label the structures of the villus below.
c. Explain how the structure of the villus is related to its role in absorption and transport of the products
of digestion.
Visible structures
Villi
Function/ effect
Increase surface area for absorption
Not visible (epithelial cells)
Function/ effect
a.
b.
Epithelium is one cell thick
Short diffusion path of molecules from lumen into blood
c.
d.
Protein channels in microvilli
Channels for:
Pumps for:
10. Undigested food molecules are passed to the large intestine.
a. Outline the functions of the large intestine.
Large intestine
Folds and Villi
Egestion
b. Distinguish between egestion and excretion.
c. List four materials that are egested in feces.
d. Discuss the benefits of a high-fibre diet.
Works Cited
1. Council-Garcia, Cara Lea. Biological Macromolecules. Univesiy of New Mexico Biology. [Online] [Cited: October
31, 2010.] http://biology.unm.edu/ccouncil/Biology_124/Summaries/Macromol.html.
2. Allott, Andrew. IB Study Guide: Biology for the IB Diploma. s.l. : Oxford University Press, 2007. 978-0-19915143-1.
3. Taylor, Stephen. Digestion Core. Science Video Resources. [Online] October 31, 2010.
http://sciencevideos.wordpress.com/bis-ib-diploma-programme-biology/06-human-health-physiology/digestion/.