Transformation
of Energy
Through
Digestion
Energy Transformations
Energy transformation is the process of
changing energy from one form to
another. Energy transformations take
place constantly around us.
-Radiant energy from the sun is
converted to chemical energy by
plants.
-Chemical energy in gasoline is
converted to mechanical energy when
our cars move.
Digestion involves both physical
and chemical changes.
Digestion is needed to break down
complex carbohydrates, proteins &
fats into molecule that are small
enough to get to the cells of the
body.
Two Types of Digestion
Mechanical Digestion

Physical Process

Breaks down food
into smaller pieces

Begins in the mouth
with the teeth &
tongue

Most occurs in
stomach
Chemical Digestion
Chemical process
 Acids from your digestive
system chemically break
food down into smaller
molecules
 Begins in the mouth with
saliva
 Most occurs in small
intestine

 During
chemical digestion,
complex carbohydrates like
starch are broken down into
simpler carbohydrates like
sugar, which are small enough
to be absorbed into the
bloodstream.
Chemical  Chemical
 The
chemical energy in
food can be converted to
another form of chemical
energy when it is stored as
glucose or fat.
Chemical  Thermal
 The
chemical energy in
food can be converted to
thermal energy because
our body produces heat
when digesting our food.
Chemical  Mechanical
 The
chemical energy in our
food can also be
converted to mechanical
energy in the form of
muscle movement.
Chemical  Mechanical  Thermal
 Your
body transforms
chemical energy from food
into mechanical energy (to
move your body), then it is
transformed into thermal
energy (your body putting
off heat).
 When
energy is absorbed,
released or transformed from
one type into another, a
chemical change has
occurred.