An Introduction to
Photosynthesis
BENCHMARKS:
SC.912.L.14.7*
SC.912.L.18.7-Identify
the reactants, products,
and basic functions of
photosynthesis.
SC.912.L.18.9*- Explain
the interrelated nature of
photosynthesis and cellular
respiration.
OBJECTIVES:
 I will state the overall equation of
photosynthesis.
 I will explain how photosynthesis
and cellular respiration are part of
an interrelated cycle.
 I will describe the factors that
affect photosynthesis.
REVIEW
What are autotrophs and
heterotrophs?
Plants, algae, and some
bacteria are able to use light
energy from the sun to produce
food.
They are called
photosynthetic autotrophs.
Animals, fungi, protozoa, and
some bacteria obtain their energy
from the food they consume.
They are called heterotrophs.
Take Notes
What is photosynthesis?
Comes from the Greek words:
photo - light
synthesis - putting together
Therefore, it
means “using light to put
something together”
During photosynthesis, plants use the
energy from sunlight to convert water and
carbon dioxide into carbohydrates and
oxygen. The energy is now STORED in the
carbohydrate molecule.
 6CO2 + 6H2O+ light
C6H12O6 + 6O2
Take Notes
How are photosynthesis and
cellular respiration related?
The key process for energy capture (from the sun) and
storing it as chemical energy in glucose is photosynthesis.
6CO2 + 6H2O + Light → C6H12O6 + 6O2
 Takes place in photosynthetic autotrophs only
 The energy in glucose is released during cellular
respiration by breaking down glucose and using it to
recharge ATP.
C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP
 Takes place in ALL organisms!
 Do you notice that photosynthesis and cellular respiration
are opposite reactions??!! They form a cycle!
 Photosynthesis captures and saves energy.
 Cellular respiration releases and uses the energy.

Take Notes
Why are light and pigments
needed for photosynthesis?
Plants gather the sun’s
energy with light absorbing
molecules called pigments.
Chlorophyll
Carotene
When chlorophyll absorbs
light , much of the energy is
transferred directly to electrons
in the chlorophyll molecule.
These high-energy electrons
make photosynthesis work.

Complete the Gizmo DO NOW in your Gizmo
Packet.


Guided Gizmo Warm-Up
Independent Activity A and B
Exit Slip
What do we know?
1. The overall process of photosynthesis can be
represented using a chemical equation. Like all chemical
equations, the equation for photosynthesis must obey
the law of conservation of mass. Which of the following
is the correct and balanced equation for
photosynthesis?
A.
CO2 + H2O
C6H12O6 + O2
B.
6CO2 + H2O
C6H12O6 + O2
C.
CO2 + 6H2O
C6H12O6 + 6O2
D.
6CO2 + 6H2O
C6H12O6 + 6O2
Exit Slip
What do we know?
2. Which of these statements correctly
describes the process of photosynthesis?
A. Photosynthesis is an exothermic
process because it releases energy.
B. Photosynthesis is an endothermic
process because it releases energy.
C. Photosynthesis is an endothermic
process because it requires the
absorption of energy.
D. Photosynthesis is an exothermic
process because it requires the
absorption of energy.
Exit Slip
What do we know?
3. Which of these best describes
the conversion of sunlight into
the energy in glucose?
A. Chemical energy is converted to
kinetic energy.
B. Kinetic energy is converted to
potential energy.
C. Electromagnetic energy is
converted to chemical energy.
D. Potential energy is converted to
electromagnetic energy.
What do we know?
Exit Slip
Scientists are measuring the rate at which carbon
dioxide (CO2) and water are converted to glucose
and oxygen (O2) per hour in various types of
houseplants with the same biomass. The
houseplants are all exposed to the same amount of
sunlight and to the same conditions. The data they
collect is given in the table.
ALOE VERA
COLEUS
POTHOS
SPIDER PLANT
AMOUNT OF
CO2
ABSORBED
180 mL
168 mL
164 mL
175 mL
AMOUNT OF
O2 RELEASED
150 mL
150 mL
150 mL
150 mL
Exit Slip
What do we know?
4. What is the most likely reason that the plants
absorb different amounts of CO2?
A.
The plants are different heights.
B.
The plants have different masses.
C.
The plants have different size leaves.
D.
The plants are different shades of green.
ALOE VERA
COLEUS
POTHOS
SPIDER PLANT
AMOUNT OF
CO2
ABSORBED
180 mL
168 mL
164 mL
175 mL
AMOUNT OF
O2 RELEASED
150 mL
150 mL
150 mL
150 mL
Exit Slip
What do we know?
5. In which process do these plants absorb CO2, water,
and sunlight to produce glucose and O2?
A.
mitosis
B.
photosynthesis
C.
replication
D.
respiration
ALOE VERA
COLEUS
POTHOS
SPIDER PLANT
AMOUNT OF
CO2
ABSORBED
180 mL
168 mL
164 mL
175 mL
AMOUNT OF
O2 RELEASED
150 mL
150 mL
150 mL
150 mL
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New Path Learning - http://www.newpathlearning.com/store/bycategory/white-board/multimedia-lessons/photosynthesisrespiration-multimedia-lesson-6468.html
Elodea Oxygen Bubble Lab http://www.saddleworth.oldham.sch.uk/science/simulations/wat
erweed.htm
Biology Corner http://www.biologycorner.com/worksheets/waterweed_sim.html
Photosynthesis Virtual Lab http://www.syngenta.com/country/uk/en/learning-zone/sciencelab/experiments/Pages/Photosynthesis_in_Action.aspx