1. 8-3 The Reactions of Photosynthesis
The reactants are:
H2O (water)
CO2 (carbon Dioxide)
The Products are:
O2 (Oxygen)
C6H12O6 (CH2O in the picture is a sugar building block for glucose)
Photo Credit: ©Stone
Should we sing the song again?
Or rap photosynthesis?
Or Linkin Park?
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Inside a Chloroplast
Inside a Chloroplast
In plants, photosynthesis takes place inside chloroplasts.
Plant
Chloroplast
Plant cells
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Inside a Chloroplast
Chloroplasts contain thylakoids—saclike photosynthetic membranes.
Single
thylakoid
Chloroplast
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Inside a Chloroplast
Thylakoids are arranged in stacks known as grana. A singular stack is called a granum.
Granum
Chloroplast
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Inside a Chloroplast
Proteins in the thylakoid membrane organize chlorophyll and other pigments into clusters called photosystems, which are the light-collecting units of the chloroplast.
Photosystems
Chloroplast
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6. Light- dependent reactions
Inside a Chloroplast
H2O
CO2
Light
NADP+
ADP + P
Light- dependent reactions
Calvin Cycle
Calvin cycle
The process of photosynthesis includes the light-dependent reactions as well as the Calvin cycle.
Chloroplast O2
Sugars
Or rap photosynthesis?
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Electron Carriers
Electron Carriers
When electrons in chlorophyll absorb sunlight, the electrons gain a great deal of energy.
Cells use electron carriers to transport these high-energy electrons from chlorophyll to other molecules.
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Electron Carriers
One electron carrier molecule is NADP+. It transports electrons:
NADP+ accepts and holds 2 high-energy electrons along with a hydrogen ion (H+)
This converts the NADP+ into NADPH.
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9. Light-Dependent Reactions
produce O2, oxygen gas
convert ADP into ATP and NADP+ into NADPH.
Video animation inside cell membrane.
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10. Light-Dependent Reactions
Because of this system, light-dependent electron transport produces not only high-energy electrons but ATP as well.
ATP synthase
+ O2
2H2O
The light-dependent reactions use energy from sunlight to produce ATP, NADPH, and oxygen.
ADP
2 NADP+ 2 2
NADPH
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The Calvin Cycle
What is the Calvin cycle?
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The Calvin Cycle
The Calvin cycle uses ATP and NADPH from the light-dependent reactions and produces high-energy sugars (glucose).
Because the Calvin cycle does not require light, these reactions are also called the light-independent reactions.
Photosynthesis-Calvin Cycle and Cyclic Electron Flow Song
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13. 5-Carbon Molecules Regenerated Sugars and other compounds
The Calvin Cycle
Reactants and Products of the Light Independent Reactions (Calvin Cycle). 12
12 ADP
6 ADP 12
NADPH 6
The Calvin cycle uses ATP and NADPH to produce high-energy sugars.
12 NADP+
5-Carbon Molecules Regenerated
Sugars and other compounds
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The Calvin Cycle
The two sets of photosynthetic reactions work together.
The light-dependent reactions trap sunlight energy in chemical form.
The light-independent reactions use that chemical energy to produce stable, high-energy sugars from carbon dioxide and water.
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8-3
In plants, photosynthesis takes place inside the
thylakoids.
chloroplasts.
photosystems.
chlorophyll.
Photosynthesis Rap (again):
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8-3
Energy to make ATP in the chloroplast comes most directly from
hydrogen ions flowing through an enzyme in the thylakoid membrane.
transfer of a phosphate from ADP.
electrons moving through the electron transport chain.
electrons transferred directly from NADPH.
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8-3
NADPH is produced in light-dependent reactions and carries energy in the form of
ATP.
high-energy electrons.
low-energy electrons.
ADP.
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8-3
What is another name for the Calvin cycle?
light-dependent reactions
light-independent reactions
electron transport chain
photosynthesis
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8-3
Which of the following factors does NOT directly affect photosynthesis?
wind
water supply
temperature
light intensity
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20. Organize the overall reaction+ O2
C6H12O6
CO2
Photosynthesis
H2O
Products
sunlight
Reactants +

21. Organize the Light Reaction reaction+ O2
sunlight
ATP
Reactants
Thylakoid Membrane
Light Reaction
Products
NADPH +
H2O + H+ +