Plants and some other types of
organisms are able to use light energy
from the sun to produce their own food.
Autotrophs – make their own food
Heterotrophs – obtain energy from the
foods they consume or absorb.
All organisms must release the energy
in sugars and other compounds.
Go to
Section:
Adenine
Go to
Section:
ATP
Ribose
3 Phosphate groups
ATP
ADP
Section 8-1
Energy
Energy
Adenosine diphosphate (ADP) + Phosphate
Partially
charged
battery
Go to
Section:
Adenosine triphosphate (ATP)
Fully
charged
battery
ATP
ADP
Section 8-1
Energy
Energy
Adenosine diphosphate (ADP) + Phosphate
Partially
charged
battery
Go to
Section:
Adenosine triphosphate (ATP)
Fully
charged
battery
If ATP is such a useful source of energy, why do
most cells have only enough ATP to last them for a
few seconds of activity?
o ATP is a great molecule for transferring energy; it is not a
good molecule for storing large amounts of energy over the
long term.
o A single molecule of glucose stores more than 90 times the
chemical energy of a molecule of ATP.
o It is more efficient for cells to keep only a small supply of
ATP on hand.
o Cells regenerate ATP from ADP as needed by using the
energy in glucose.
Go to
Section:
Light and Pigments
In addition to water and carbon dioxide, photosynthesis
requires light and chlorophyll, a molecule in chloroplasts.
Sunlight is a mixture of different wavelengths of light.
Plants gather the sun’s energy with light-absorbing
molecules called pigments.
Chlorophyll is the plants’ principle pigment (chlorophyll a
and chlorophyll b).
Chlorophyll absorbs light in the blue-violet and red
regions of the visible spectrum. Green light is reflected by
leaves.
When chlorophyll absorbs light, the energy from the sun
is transferred to the electrons of the chlorophyll molecule.
Go to
Section:
Figure 8-5 Chlorophyll Light Absorption
Section 8-2
Absorption of Light by
Chlorophyll a and Chlorophyll b
Chlorophyll b
Chlorophyll a
V
Go to
Section:
B
G
YO
R
Photosynthesis: Reactants and Products
Section 8-2
Light Energy
Chloroplast
CO2 + H2O
Go to
Section:
Sugars + O2
Go to
Section:
Go to
Section:
Figure 8-7 Photosynthesis: An Overview
Section 8-3
Chloroplast
Light
H2O
CO2
Chloroplast
NADP+
ADP + P
LightDependent
Reactions
Calvin
Cycle
ATP
NADPH
O2
Go to
Section:
Sugars
Figure 8-10 Light-Dependent Reactions
Light-Dependent Reactions
Section 8-3
Photosystem II
Hydrogen
Ion Movement
Chloroplast
ATP synthase
Inner
Thylakoid
Space
Thylakoid
Membrane
Stroma
Electron
Transport Chain
Go to
Section:
Photosystem I
ATP Formation
Figure 8-11 Calvin Cycle
Section 8-3
Calvin Cycle
CO2 Enters the Cycle
Energy Input
ChloropIast
5-Carbon
Molecules
Regenerated
6-Carbon Sugar
Produced
Sugars and other compounds
Go to
Section:
Factors that affect the rate of photosynthesis:
•Availability of water
•Light intensity
•Temperature
Go to
Section:
Concept Map
Section 8-3
Photosynthesis
includes
H2O
Lightdependent
reactions
Calvin cycle
use
take place in
Energy from
sunlight
Thylakoid
membranes
to produce
ATP
NADPH
Go to
Section:
O2
takes place in
Stroma
CO2
uses
ATP
NADPH
of
to produce
Chloroplasts
High-energy
sugars