Cell Biology
Chapter Eight: Cell Processes
• 8.1 The Cell Membrane
• 8.2 Cells and Energy
Investigation 8B
Photosynthesis and Color
• Does the color of light affect photosynthesis?
8.2 What is photosynthesis?
In photosynthesis, plants
take in carbon dioxide
and water and release
glucose and oxygen
wastes.
• Photosynthesis is a
chemical reaction that
takes place in the
chloroplasts of plant
cells.
• During photosynthesis,
plants use the energy of
sunlight to produce
energy-rich molecules
called carbohydrates
(ex. glucose).
8.2 What is photosynthesis?
• Chloroplasts are
where photosynthesis
occurs.
• Chloroplasts work
much like solar cells
found in calculators.
8.2 Light and color
• The Sun provides
Earth with a steady
source of light.
• Your eyes see sunlight
as white light, but it is
really made up of
different colors of light.
A clear prism can split white
light into a rainbow of color.
8.2 Light and color
• Light is part of a collection of waves known as
the electromagnetic spectrum.
• Waves can be described by their wavelength
(length from peak to peak), and their energy.
8.2 Light and color
• Color is how we experience the energy of
light.
8.2 Chlorophyll
• A pigment is a
molecule that
absorbs some
colors of light and
reflects others.
• Chlorophyll is the
main pigment used
in photosynthesis.
8.2 Chlorophyll
• Chlorophyll
absorbs mostly
blue and red
light, and reflects
green light.
• This is why most
plants look green.
8.2 Cellular respiration
• Cellular respiration
is a chemical reaction
that occurs in all
living things.
• Cells use oxygen and
glucose to produce
carbon dioxide, water,
and energy.
8.2 Cellular respiration
• In most eukaryotic
organisms, cellular
respiration takes place in
the mitochondria of cells.
• During cellular respiration,
energy is stored in a
molecule called ATP while
some energy is released as
heat.
8.2 Comparing photosynthesis
and respiration
• The chemical equations of photosynthesis
and respiration have an interesting
relationship.
• The reactants in photosynthesis are the
products in cellular respiration!
• The reactants in cellular respiration are
the products in photosynthesis!
Research
Connection
Amazing Cells
• So how do stem
cells change into
other types of cells?
• Scientists are
studying this
problem.
Activity
Making a Concept Map
• A concept map is a
way to represent
information visually.
• Create a concept
map to explain how
cells get and use
energy.