Photosynthesis
and
Respiration
What you will learn:
• Photosynthesis and Cellular Respiration
are complementary processes that
depend on each other.
Photosynthesis Reaction
What is the equation for photosynthesis?
carbon dioxide + water + energy  glucose + oxygen
6CO2 + 6H2O + energy  C6H12O6 + 6O2
Photosynthesis Reaction
This is why plants breathe
in carbon dioxide.
This is why we can eat
plants to get energy.
6CO2 + 6H2O + energy  C6H12O6 + 6O2
This is why plants
need sunlight.
This is why plants
need water.
This is why plants
produce oxygen.
Where Does it Occur?
Photosynthesis
• Occurs in the Chloroplast
• Chloroplasts contain
chlorophyll. the green
pigment that can trap
sunlight.
• Plants, algae, and certain
bacteria contain these
chloroplasts.
Equation for Cellular Respiration
Glucose
Oxygen
Water
Energy
Visual Summary 6.3
Equation for Cellular Respiration
This is why we eat.
Plants don’t eat;
they make this with
sunlight.
Glucose
Oxygen
This is why we
breathe oxygen.
The energy released from
the glucose is stored in
molecules of ATP for later
use.
Carbon Dioxide
This is why we
breathe out
carbon dioxide.
Water
Energy
The water
we can use.
Where Does it Occur?
Cellular Respiration
• Occurs in the mitochondria
• Here the energy released
from glucose is stored in ATP
molecules.
• Most organisms have these.
Respiration vs. Photosynthesis
Photosynthesis and respiration are complementary
processes in the living world. They are opposite
processes, and neither can exist without the other.
Respiration vs. Photosynthesis
Photosynthesis uses carbon dioxide, water, and
the energy of sunlight to produce glucose
(sugar) and oxygen.
Respiration vs. Photosynthesis
Respiration is a process that uses oxygen and glucose to
form Carbon dioxide, water and energy.
Respiration vs. Photosynthesis
In respiration, organisms obtain the energy that
they need to survive from the food that plants
produced.
Cellular Respiration -vsPhotosynthesis
Photosynthesis
Respiration
Organisms
Plants, algae, some
bacteria
Most organisms
(Including plants)
Needed
CO2, H2O, chlorophyll,
sun
Glucose, O2
Produced
Glucose, O2
CO2, H2O, ATP
When occurs
daylight
night and day
Where occurs
Chloroplast in cell
Mitochondria of cell
SUMMARY OF KEY CONCEPTS
Heat
Sunlight
Photosynthesis
Cellular
respiration
Review Question # 1
1. What of these is not needed for
photosynthesis?
A. carbon dioxide
B. oxygen
C. water
D. energy
Review Question # 1
1. What of these is not needed for
photosynthesis?
A. carbon dioxide
B. oxygen
C. water
D. energy
Review Question # 2
2. Respiration happens in
A. animals
B. plants
C. neither plants nor animals
D. both plants and animals
Review Question # 2
2. Respiration happens in
A. animals
B. plants
C. neither plants nor animals
D. both plants and animals
Review Question # 3
3. In respiration the released energy is
stored in molecules of
A. glucose
B. DNA
C. carbon dioxide
D. ATP
Review Question # 3
3. In respiration the released energy is
stored in molecules of
A. glucose
B. DNA
C. carbon dioxide
D. ATP
Review Question # 4
4. Which statement about photosynthesis is
most correct?
A. The reaction is exothermic.
B. Energy is required to construct the
glucose molecules.
C. Energy is released in the reaction.
D. ATP molecules are used to start the
reaction.
Review Question # 4
4. Which statement about photosynthesis is
most correct?
A. The reaction is exothermic.
B. Energy is required to construct the
glucose molecules.
C. Energy is released in the reaction.
D. ATP molecules are used to start the
reaction.
Review Question # 5
5. Which statement about respiration is not
correct?
A. The reaction is exothermic.
B. Energy is required to construct the
glucose molecules.
C. Energy is released in the reaction.
D. Energy released is used to create ATP
molecules.
Review Question # 5
5. Which statement about respiration is not
correct?
A. The reaction is exothermic.
B. Energy is required to construct the
glucose molecules.
C. Energy is released in the reaction.
D. Energy released is used to create ATP
molecules.
Review Question # 6
6. Which chemical is not a product of
respiration?
A. carbon dioxide
B. ATP
C. oxygen
D. water
Review Question # 6
6. Which chemical is not a product of
respiration?
A. carbon dioxide
B. ATP
C. oxygen
D. water
Review Question # 7
7. Chlorophyll
A. makes glucose
B. traps sunlight energy
C. produces oxygen
D. produces carbon dioxide
Review Question # 7
7. Chlorophyll
A. makes glucose
B. traps sunlight energy
C. produces oxygen
D. produces carbon dioxide
Review Question # 8
8. Where does respiration happen?
A. in the mitochondria
B. in ATP
C. in the chloroplast
D. in glucose molecules
Review Question # 8
8. Where does respiration happen?
A. in the mitochondria
B. in ATP
C. in the chloroplast
D. in glucose molecules
Review Question # 9
9. We breathe oxygen because
A. it is needed to make glucose molecules.
B. it is needed to make ATP molecules.
C. it is needed to break apart ATP
molecules.
D. it is needed to break apart glucose
molecules.
Review Question # 9
9. We breathe oxygen because
A. it is needed to make glucose molecules.
B. it is needed to make ATP molecules.
C. it is needed to break apart ATP
molecules.
D. it is needed to break apart glucose
molecules.
Review Question # 10
10. Which is the correct formula for
photosynthesis?
A) C6H12O6 + 6O2 + energy  6CO2 + 6H2O
B) 6CO2 + 6H2O  C6H12O6 + 6O2 + energy
C) 6CO2 + 6H2O + energy  C6H12O6 + 6O2
D) C6H12O6 + 6O2  6CO2 + 6H2O + energy
Review Question # 10
10. Which is the correct formula for
photosynthesis?
A) C6H12O6 + 6O2 + energy  6CO2 + 6H2O
B) 6CO2 + 6H2O  C6H12O6 + 6O2 + energy
C) 6CO2 + 6H2O + energy  C6H12O6 + 6O2
D) C6H12O6 + 6O2  6CO2 + 6H2O + energy
Review Question # 11
11. Which is the correct formula for
cellular respiration?
A) C6H12O6 + 6O2 + energy  6CO2 + 6H2O
B) 6CO2 + 6H2O  C6H12O6 + 6O2 + energy
C) 6CO2 + 6H2O + energy  C6H12O6 + 6O2
D) C6H12O6 + 6O2  6CO2 + 6H2O + energy
Review Question # 11
11. Which is the correct formula for
cellular respiration?
A) C6H12O6 + 6O2 + energy  6CO2 + 6H2O
B) 6CO2 + 6H2O  C6H12O6 + 6O2 + energy
C) 6CO2 + 6H2O + energy  C6H12O6 + 6O2
D) C6H12O6 + 6O2  6CO2 + 6H2O + energy
Review Question # 12
12. Which statement best shows the
relationship between photosynthesis and
cellular respiration?
A) They both need the same reacting chemicals.
B) They both produce the same products.
C) They are opposite processes, each needing the
other’s products.
D) They are opposite processes, each needing oxygen
to occur.
Review Question # 12
12. Which statement best shows the
relationship between photosynthesis and
cellular respiration?
A) They both involve oxygen as a part of the chemical
reaction.
B) They both are processes involving energy.
C) They are opposite processes, each needing the
other’s products.
D) They are opposite processes, each needing oxygen
to occur.