When do you use
energy?
List all of the ways you
have used energy today.
Without the ability
to obtain and use
energy, life would
not exist.
Forms of Energy
Energy comes in many forms:
Light
Heat
Electricity
 . . . Energy can also be stored
in the bonds of chemical
compounds.
2 types of energy in living
things
Autotrophs- organisms that get their
energy directly from the sun.

Examples:
Heterotroph- Organisms that eat food to
obtain their energy.

Examples:
ALL energy begins with the sun!
How does a heterotroph get energy from
the sun?
Chemical Energy
The main compound cells
use to store and release
energy = ATP
Complete ATP Worksheet!
Important Scientists
Van Helmont- Wondered if plants grew by taking mass
out of the soil?
- Measured the soil, planted a seed and
watered the plant until it grew.
- After 5 years, plants weighed 75 kg and
the soil was unchanged!
Concluded- water (hydrate) that made the
plant grow!
Another Scientist
Priestley
Light a candle, put a glass jar over it
 Candle goes out immediately!

Second time lit a candle with a sprig of
fresh mint
 Candle burned for much longer than without
mint.

Why?
 Mint produces oxygen- necessary to burn!
Last Scientist
Ingenhousz


Added to Priestly’s experiment
Concluded that plant must be exposed to
light in order for “Priestly” effect to work.
No light, no photosynthesis!
The two cell energy
processes we will
discuss =
Photosynthesis
Cellular Respiration

TO DO
In your notebook write the following equations.
1. Show ATP breaking down to ADP
2. Show ADP capturing energy to make ATP
TO DO #2
Write the following equations in your notebook.
(should use a new page)
1. Write the chemical equation for
photosynthesis
2. Write the photosynthesis equation out in
words.
3. Write the photosynthesis equation out in
pictures. Be sure to add color!
CHAPTER 8
PAGE 201
Definition: The
conversion of light
energy into chemical
energy stored in
organic compounds
Who can do this? …Plants and Algae
In other words, remember this:
carbon dioxide + water + light
energy = glucose + oxygen
As a chemical reaction it's like so:
6CO2 +6H2O = C6H12O6 + 6O2
Photosynthesis Equation
Learn the song! It will help!
On a separate sheet of paper
(next page of notes)
1. Write the chemical equation for
photosynthesis
2. Write the equation for photosynthesis out
in words
3. Write out the equation for photosynthesis
in pictures! Use the colored pencils!
Where does it happen?
Within the CHLOROPLAST
of a plant cell
Draw & label
in notes!
•Photosynthesis begins with
the absorption of light by
pigments in the thylakoids
•Main pigments in plants =
chlorophyll. It absorbs all
colors of light, and reflects
back green.
Light and Pigments
In addition to water and carbon dioxide,
photosynthesis requires light and
chlorophyll.

Chlorophyll is found in chloroplast! (green)
Plants gather the sun’s light in pigments.
(light absorbing molecules)
Since light is a form of energy, anything that
absorbs light is also absorbing energy!
Chlorophyll Absorption
Complete handout activity on
chlorophyll absorption!
DO NOW: Pigments
1. Write the balanced chemical equation
for photosynthesis.
2. What pigment does the chloroplast
contain?
3. What does the pigment do in a
plant?
Photosynthesis Lab
1. Use your textbook, page 206 for setup
instructions.
2. Once your lab group has your lab set up
please return to your seats. Be sure to leave
your lab area clean!
3. After we return to your lab answer
questions 1-3.
Photosynthetic Processes
Light Reactions- Trap the energy from
sunlight.
Calvin Cycle- use energy from light
reactions to produce sugars. Carbon
Dioxide and Water are needed with light,
sugar is produced and oxygen given off!
(remember equation)
A. Light Reactions
1. Reaction occurs in the
membrane of the thylakoid
Chloroplast
Circle on the
diagram
you drew.
A. Light Reactions-con’t
2. Light excites e- in
chlorophyll pigments (e- go
from low energy to high
energy)
3. e- travel to other
molecules in membrane,
losing energy along the way
Final Step:
4. e- combine to make…
ADP + phosphate + e-
ATP
When the bond in ATP is
broken, energy is released!
TO DO: Photosynthesis
1. What is the complete chemical equation for
photosynthesis?
2. Where does photosynthesis take place
- What organelle?
- What part of the organelle?
- Light Reactions- Dark Reactions-
3. What is formed when electrons share their
energy with other electrons?
1. Occurs in stroma of chloroplast
(circle on your diagram)
2. Uses ATP and H from light rxn.
3. ATP + H + CO2(from air) =
Photosynthesis
glucose (carb)
Animation!
Solution- STROMA
THYLAKOID
Chloroplast
The exchange
of gases
between the
leaf and the
atmosphere
occurs through
the STOMATA
Factors Affecting Photosynthesis
1. Water amounts- Shortage of water can
slow down or stop the rate of
photosynthesis.
2. Temperature- Photosynthesis likes to
occur between 0-35˚ Celsius.
3. Intensity of Light- not enough light, no
photosynthesis. Every plant needs a
different amount of light.