Download 6-1 Digestion

Lesson 6.1 Digestion
Red Book: 162-169 (reference)
1
 Large food
molecules are
polymers, which
must be broken
down into
monomers (via
hydrolysis) in order
to be absorbed into
the blood.
2
 Enzymes speed up the
rate at which polymers
are broken down into
monomers.
3
Amylase
Protease
Lipase
Example of this
enzyme
Salivary amylase Pepsin
Pancreatic lipase
Source
Salivary glands
Wall of stomach
Pancreas
Substrate
Starch
Proteins
Triglycerides
(fats and oils)
Product
Maltose
Small
polypeptides
Fatty acids and
glycerol
Optimum pH
7-8
1.5-3
7-8
4
 Locate: mouth,
esophagus, stomach,
small intestine, large
intestine, anus, liver,
pancreas, gall
bladder.
 Peristalisis: the
movement of food
through the
digestive tract.
5
 Stomach- primary site for
protein digestion.
 Small intestine- primary
site for nutrient
absorption. Epithelial
layer is 1 cell thick.
 Large intestine- water
used in the digestive
process is reabsorbed
back into the body.
6
 Absorption- the transfer
of nutrients from the
digestive tract into the
blood stream, usually
through villi in the small
intestine.
 Assimilation- uptake of
nutrients from blood
stream into body tissue.
Occurs after absorption.
7
Pictured: microvilli on a villus.
 Villi have a large surface area, gated ion channels,
and are dense in mitochondria, which provide
energy for the active transport of nutrients.
8
 The Digestive System