Digestion Unit
Summary Tables – Answer Key
Table 1: Food that carries essential nutrients is broken down during digestion into smaller particles that
can be absorbed and used by cells.
Food
Example
Rye Bread
Essential
Nutrient
Building Block
Function of Nutrient
Simple sugars
Monosaccharides
Peptides  Amino acids
Energy for your body
Turkey Slices
Complex
Carbohydrates
Protein
Oil Dressing
Lipids (fats)
Fatty acids and glycerol
Structure (plasma membrane)
and stored energy
(what is remaining after digestion)
Growth and repair
Digestion Alimentary Canal Overview
Table 2: Organs of the alimentary canal (G.I tract) have different structures because they have different
functions in both physical and chemical digestion.
Organ
Mouth
Enzymes Present
Amylase (in saliva)
Esophagus
What happens here



NONE

Stomach
Small
Intestine
Large
Intestine
Rectum
Anus
Pepsin
(gastric juice = HCl)
(Hormone gastrin = relaxes pyloric
sphincter)
 Pancreatic Juice
- Secretin (neutralize acid)
- Maltase (maltose  glucose)
- Trypsinogen (peptides 
amino acids)
- Lipase (lipids  glycerol and
fatty acids)
 Intestinal juice
-peptidase (peptides  amino
acids)
 Bile from the liver (lipids 
glycerol and fatty acids)
NONE

NONE
NONE







Mechanical digestion of all food (teeth)
Chemical digestion of carbohydrates begin
Food passes from the mouth, through the
esophagus, to the stomach (through cardiac
sphincter)
Movement by peristalsis (wavelike
contraction of muscles)
Mechanical digestion of food (rugae –
churning of stomach walls)
Chemical digestion of proteins begin
(pepsinogen converts to pepsin)
Peristalsis of S.I to move food along and
finish all mechanical digestion
Chemical digestion of carbs, protein and
lipids continues and is completed in the
small intestine.
Small, soluble nutrients are absorbed into
the villi (broken down into the basic building
blocks)
- Sugars (glucose)
- Amino acids
- Fatty acids
- glycerol
Water is absorbed from unusable,
undigestable wastes (feces)
Feces are temporarily stored
Feces are eliminated (egested) from the
body.
Digestion Accessory Organ Overview
Table 3: Accessory organs assist the alimentary canal by producing substances that are involved in
digestion.
Accessory Organ
Secretion and Function
Tongue










Help mix food with saliva
Creates a bolus
Assists in swallowing
Produces saliva (which contains the enzyme amylase)
Chemically digests carbohydrates
Moistens food to help form bolus
Produces bile (emulsifies lipids into glyceol and three fatty acid chains)
Stores excess glucose as glycogen
Stores vitamins A, B12, D (extracted from food)
Stores iron and detoxifies blood (not specific to digestion)



Stores bile
Releases it to the small intestine when required
Produces pancreatic juice (mixture of digestive enzymes) and releases it
into the small intestine during digestion of carbs, lipids and proteins.
Releases bicarbonate ions to neutralize the acidic chyme leaving the
stomach and entering the S.I (brings pH from 2 to about 9)
Releases insulin to maintain blood sugar levels
Salivary Glands
Liver
Gall Bladder
Pancreas

