Chapter 8 Notes: Photosynthesis
Concept 8.1; Photosynthesis uses light energy to make food
I. The structure of Chloroplasts
A. The structure where photosynthesis takes place is the ______________
B. Chloroplasts contain compounds called _______________ that give leaves their color
C. Leaves contain the most chloroplasts
D. There are tiny pores called _____________ that allows carbon dioxide to enter and
oxygen to leave the cell
E. Veins carry ________________ and _________________ from the plants roots to the
leaves and deliver organic compounds to other parts of the plant
F. The inner membrane of a chloroplast encloses a thick fluid called _____________
G. Suspended in the stroma are many disk shaped sacs called _______________ which
are arranged in stacks called ________________
H. These stacks organize the series of reactions that make up photosynthesis
II. Overview of Photosynthesis
A. In cellular respiration, electrons “_________” from glucose to _____________ to
release energy
B. In photosynthesis, electrons from water are boosted “________________” by the
energy of sunlight
C. These excited electrons, along with carbon dioxide and hydrogen ions to produce
_________________ molecules
D. Photosynthesis occurs in two main steps: _________________________ and
_______________________
III. The Light Reactions
A. ______________________ convert the energy in sunlight to chemical energy
B. Chloroplasts use captured light energy to remove electrons from ___________,
splitting it into oxygen and hydrogen ions.
C. The electrons and hydrogen ions are used to make ________________, which is an
electron carrier
D. Chloroplasts also use the captured light energy to generate ATP
E. The overall result of the light reactions is the conversion of _____________ energy to
______________energy stored in NADPH and ATP
IV. The Calvin Cycle
A. ___________________ makes sugar from the atoms in carbon dioxide plus the
hydrogen ions and high energy electrons carried in NADPH
B. The _________ made in the light reactions provides the energy to make ___________
C. The Calvin cycle is sometimes referred to as the “light-independent reactions”
because it does not require ______________ to begin
Concept 8.2 The Light Reactions Convert Light Energy to Chemical Energy
I. Light Energy and Pigments
A. Light is a form of energy that travels in _____________ and the distant between
adjacent waves is called a ________________
B. The range of wavelengths is called the ___________________________
C. Visible light only makes up a ________________ portion of the electromagnetic
spectrum
II. Pigments and Color
A. A substances color is due to chemical compounds called ______________
B. Waves of light shining on a material can be ____________________, transmitted or
_____________________
C. Leaves absorb blue-violet and red-orange light very well but either reflect or transmit
_______________ light and that is why leaves look green
III. Identifying Chloroplast Pigments
A. Using a technique called ____________________________ different pigments in a
leaf can be observed
B. Chlorophyll a absorbs mainly _______________ light while chlorophyll b absorbs
mainly ________________ light
IV. Harvesting Light Energy
A. Within the thykaloid membrane, chlorophyll and other molecules are arranged in
clusters called ___________________
B. Each photosystem contains a few hundred pigment molecules, including chlorophyll
a and b as well as carotenoids
C. Each time a pigment molecule absorbs light energy electrons are raised from a
“_________________” to a “___________________”
D. This electron “jumps” from molecule to molecule until it arrives at the
___________________________
E. The reaction center consists of chlorophyll a and a primary electron carrier. Other
teams of molecules are also used to make _________________ and ____________
V. Chemical Products of Light Reactions
A. ___________ photosystems are involved in the light reactions
B. The first photosystem traps _________ energy and transfers the light-excited
______________ to the electron transport chain, this can be referred to as the “water
splitting photosystem”
C. The second photosystem can be thought of as the “NADPH-producing photosystem”
This system produces ______________ by transferring excited electrons and
hydrogen ions to NAD+
D. The light reactions convert light energy to the chemical energy of ATP and NADPH,
no ___________ has been produced, which is the job of the
__________________________________________
Concept 8.3 The Calvin cycle makes sugar from carbon dioxide
I. A Trip Around the Calvin Cycle
A. The Calvin Cycle is the ____________ factory within the chloroplasts
B. The starting material for the Calvin cycle is regenerated each time the process occurs,
the starting material is called _______________, a sugar with five carbons
C. The inputs for the Calvin cycle are ________________, ___________________ and
______________________
D. The cycles output is an energy rich sugar molecule called __________ which is not
quite glucose but is used as the raw material to make glucose as the plant needs to
II. Summary of Photosynthesis
A. The overall equation for photosynthesis is
6 CO2 + 6 H2O  C6H12O6 + 6 O2
B. The light reactions take place in the _____________ membranes and convert light
energy into ____________ energy in the form of __________ and __________
C. The light reactions use the reactant ___________ and release the product
_________________
D. The Calvin cycle takes place in the ___________ uses _______ and _________ to
convert ____________ to ______________
E. Photosynthesis is the first step in the flow of energy through an _________________
F. _______________ is the ultimate source of all the ___________ you eat and all the
_______________ you breathe
Concept 8.4 Photosynthesis has a global impact
I. The Carbon Cycle
A. The ____________ cycle is the process by which carbon moves from ____________
to _________________ compounds and back
B. Through photosynthesis, producers convert inorganic carbon dioxide to organic
compounds.
C. __________________________ by both producers and consumers return the carbon
dioxide to the _____________________
D. No other chemical process matches the output of photosynthesis
E. Earth’s plants and other photosynthetic organisms make up about __________
million tons of organic material per year
II. Photosynthesis and Global Climate
A. One organism may either produce or use a relatively small amount of carbon dioxide ,
the total effect of all the organisms on Earth has a very __________ effect
B. Carbon dioxide only made up ________ percent of the Earth’s atmosphere before this
century
C. Carbon dioxide traps heat from the sun that would have otherwise escape back into
space, this property is known as the ___________________ effect
D. The greenhouse effect keeps the average temperature on Earth about ______ degrees
warmer than it would be otherwise
E. The amount of CO2 in the atmosphere is _______________ with no end in sight