[
Cellular Energy
chapter
8
Copyright © Glencoe/McGra

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

w-Hill,

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

a division of The McGraw-Hill Companies

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

, Inc.
-!). )DEA
Light energy is tr

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

apped and

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

con

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

verted into chemical energy

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

during photosynthesis

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

.
What You’ll Learn
the two phases of photosynthesis
how a chlor

Chloroplast : An organelle found in plant cells and other eukaryotic organisms that conduct photosynthesis, which captures light energy and converts it into chemical energy.

oplas

Chloroplast : An organelle found in plant cells and other eukaryotic organisms that conduct photosynthesis, which captures light energy and converts it into chemical energy.

t works during
light reactions
how electron transport works
Before You Read
Plants change energy from sunlight into energy that is used by
other living things. Describe on the lines below what would
happen to life on Earth if plants suddenly disappeared. Then
read about how plants use the Suns energy.
Identify Details As you
read, highlight or underline
the events of each stage of
photosynthesis

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

.
1. Identify one way cells
can use glucose

Glucose : A simple sugar produced during the Calvin Cycle that can be used as energy or for building complex carbohydrates.

.
section Photosynthesis
2
Read to Learn

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

Overview of Photosynthesis

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

Photosynthesis is the process in which light energy from
the Sun is changed into chemical energy. Nearly all life on
Earth depends on photosynthesis. The chemical equation fo

chemical equation for photosynthesis is 6co2 6h2o c6h12o6 6o2 : This equation summarizes the photosynthesis process where carbon dioxide and water are used to produce glucose and oxygen, necessary for energy and respiration in most living beings.

r
photosynthesis is

chemical equation for photosynthesis is 6co2 6h2o c6h12o6 6o2 : This equation summarizes the photosynthesis process where carbon dioxide and water are used to produce glucose and oxygen, necessary for energy and respiration in most living beings.

shown below.
6CO2 6H2O C
6H12O6 6O2
Photosynthesis oc

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

curs in

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

two phases. In phase one—th

ATP : Adenosine triphosphate, a high-energy molecule found in the cells of all living things, storing energy required for various cellular processes.

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

e
light-dependent reactions

phase one light dependent reactions phase two light independent reactions : Photosynthesis occurs in two steps where light-dependent reactions capture light energy, and light-independent reactions use the captured energy to synthesize glucose.

Light-dependent reactions : The first phase of photosynthesis where solar energy is absorbed and converted into chemical energy in the form of ATP and NADPH.

—light energy is absorbed and

ATP : Adenosine triphosphate, a high-energy molecule found in the cells of all living things, storing energy required for various cellular processes.

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

changed into c

ATP : Adenosine triphosphate, a high-energy molecule found in the cells of all living things, storing energy required for various cellular processes.

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

hemical energ

ATP : Adenosine triphosphate, a high-energy molecule found in the cells of all living things, storing energy required for various cellular processes.

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

y in the form of

ATP : Adenosine triphosphate, a high-energy molecule found in the cells of all living things, storing energy required for various cellular processes.

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

ATP and
NADPH.

NADPH : An electron carrier that provides high-energy electrons for the light-independent reactions of photosynthesis.

NADP+ : Nicotinamide adenine dinucleotide phosphate, an electron carrier molecule that transfers high-energy electrons from chlorophyll to other molecules.

In phase two—the light-independent reactions

Light-independent reactions : The second phase of photosynthesis, also known as the Calvin cycle, which takes place in the stroma of chloroplasts, using ATP and NADPH to synthesize glucose.

—the ATP
and NADPH that were formed in phase one are used to
make gluc

Glucose : A simple sugar produced during the Calvin Cycle that can be used as energy or for building complex carbohydrates.

ose. Glucose can then be joined with other simple
sugars to form larger molecules such as complex sugars
and carbohydrates. Sugar can also be changed into other
molecules needed by the cell, such as proteins, lipids, and
nucleic acids.
light
86
Chapter 8 Cellular Energy Reading Essentials
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Copyright © Glencoe/McGra

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

w-Hill,

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

a division of The McGraw-Hill Companies

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

, Inc.
Phase One: Light Reactions

phase one light dependent reactions phase two light independent reactions : Photosynthesis occurs in two steps where light-dependent reactions capture light energy, and light-independent reactions use the captured energy to synthesize glucose.

Light-dependent reactions : The first phase of photosynthesis where solar energy is absorbed and converted into chemical energy in the form of ATP and NADPH.

Light-independent reactions : The second phase of photosynthesis, also known as the Calvin cycle, which takes place in the stroma of chloroplasts, using ATP and NADPH to synthesize glucose.

Plants hav

chloroplasts are large organelles that capture light energy from the sun : Chloroplasts, found in plants and some other organisms, are essential for harnessing solar energy needed for photosynthesis.

Chloroplast : An organelle found in plant cells and other eukaryotic organisms that conduct photosynthesis, which captures light energy and converts it into chemical energy.

e special organelles called chloroplasts t

chloroplasts are large organelles that capture light energy from the sun : Chloroplasts, found in plants and some other organisms, are essential for harnessing solar energy needed for photosynthesis.

Chloroplast : An organelle found in plant cells and other eukaryotic organisms that conduct photosynthesis, which captures light energy and converts it into chemical energy.

o

chloroplasts are large organelles that capture light energy from the sun : Chloroplasts, found in plants and some other organisms, are essential for harnessing solar energy needed for photosynthesis.

Chloroplast : An organelle found in plant cells and other eukaryotic organisms that conduct photosynthesis, which captures light energy and converts it into chemical energy.

capture light energy

chloroplasts are large organelles that capture light energy from the sun : Chloroplasts, found in plants and some other organisms, are essential for harnessing solar energy needed for photosynthesis.

Chloroplast : An organelle found in plant cells and other eukaryotic organisms that conduct photosynthesis, which captures light energy and converts it into chemical energy.

. Photosynthesis be

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

gins when sunlight

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

is captured. The captured energy is stored in two energy
storage molecules—ATP and NADPH—that will be used
in light-independent reactions.
What happens in chloroplasts?
Chloroplasts are large organelles that capture light
energy from the Sun. They are found in plants and other
photosynthetic organisms. The fi gure below shows
a chloroplast.
A chloroplast is a disc-shaped organelle that contains two
compartments. Thylakoids (THI la koyds) are fl attened

Thylakoid Membrane : A membrane-bound compartment inside chloroplasts and cyanobacteria where the light-dependent reactions of photosynthesis take place.

saclike membranes.

Thylakoid Membrane : A membrane-bound compartment inside chloroplasts and cyanobacteria where the light-dependent reactions of photosynthesis take place.

The thyla

thylakoids and grana are structures within chloroplasts : Thylakoids are flattened sac-like membranes arranged in stacks called grana, playing a critical role in capturing and converting light energy.

grana : Stacks of thylakoids embedded in the stroma of a chloroplast

koids are arranged in stacks

thylakoids and grana are structures within chloroplasts : Thylakoids are flattened sac-like membranes arranged in stacks called grana, playing a critical role in capturing and converting light energy.

grana : Stacks of thylakoids embedded in the stroma of a chloroplast

called

thylakoids and grana are structures within chloroplasts : Thylakoids are flattened sac-like membranes arranged in stacks called grana, playing a critical role in capturing and converting light energy.

grana : Stacks of thylakoids embedded in the stroma of a chloroplast

gran

thylakoids and grana are structures within chloroplasts : Thylakoids are flattened sac-like membranes arranged in stacks called grana, playing a critical role in capturing and converting light energy.

grana : Stacks of thylakoids embedded in the stroma of a chloroplast

a. The fl uid-fi lled space outside the grana is the
strom

Stroma : The fluid-filled space surrounding the grana inside the chloroplast where the light-independent reactions of photosynthesis, or the Calvin cycle, take place.

a. Phase one takes place in the thylakoid

Thylakoid : A membrane-bound compartment inside chloroplasts, the site of the light-dependent reactions of photosynthesis.

s. Phase two
takes place in the stroma.
2. Name Which organism
has chloroplas

Chloroplast : An organelle found in plant cells and other eukaryotic organisms that conduct photosynthesis, which captures light energy and converts it into chemical energy.

ts? (Circle
your answer.)
a. mushroo

mushroom : A type of fungus, not involved in photosynthesis

m
b. oa

oak tree : A type of tree that performs photosynthesis

k tree

oak tree : A type of tree that performs photosynthesis

c. ea

earthworm : An organism that does not perform photosynthesis

rthworm

earthworm : An organism that does not perform photosynthesis

Picture This
3. Illustrate In the box,
draw an enlarged picture
of a granum

Granum : A stack of thylakoids within the chloroplast, involved in the light-dependent reactions of photosynthesis.

.
4. Explain Why do the
leaves of some trees
change colors in autumn?
Gran

grana : Stacks of thylakoids embedded in the stroma of a chloroplast

um
Thylakoid

Thylakoid : A membrane-bound compartment inside chloroplasts, the site of the light-dependent reactions of photosynthesis.

Thylakoid Membrane : A membrane-bound compartment inside chloroplasts and cyanobacteria where the light-dependent reactions of photosynthesis take place.

Location of
phase one
Strom

Stroma : The fluid-filled space surrounding the grana inside the chloroplast where the light-independent reactions of photosynthesis, or the Calvin cycle, take place.

a—
location of
phase two
Outer
membrane
Inner
membrane
Chloroplas

thylakoids and grana are structures within chloroplasts : Thylakoids are flattened sac-like membranes arranged in stacks called grana, playing a critical role in capturing and converting light energy.

Chloroplast : An organelle found in plant cells and other eukaryotic organisms that conduct photosynthesis, which captures light energy and converts it into chemical energy.

Chlorophyll : A green pigment found in chloroplasts that is responsible for the absorption of light to provide energy for photosynthesis.

t
What is the role of pigments in photosynthesis

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

?
Thylakoids contain light-absorbing colored molecules known
as pigments. Different pigments absorb different wavelengths
of light. Chlor

chlorophylls absorb energy from violet blue light and reflect green light : The green color of plants is due to chlorophylls which primarily absorb violet-blue light effectively, reflecting green, hence the plant's visual color.

ophylls are the major light-absorbing pigments

chlorophylls absorb energy from violet blue light and reflect green light : The green color of plants is due to chlorophylls which primarily absorb violet-blue light effectively, reflecting green, hence the plant's visual color.

in plants. They absorb energy from violet-blue light and refl ect
green light, giving plants their green color.
Accessory pigments help plants absorb additional light.
For instance, carotenoids (kuh

carotenoids absorb blue and green light and reflect yellow orange and red light : Additional pigments like carotenoids help in maximizing light absorption, explaining the varied colors in plants, especially seen during autumn.

Carotenoids : Pigments that absorb light mainly in the blue and green regions and reflect light in the yellow, orange, and red regions, contributing to the colors of many fruits and vegetables.

ROH tuh noy

carotenoids absorb blue and green light and reflect yellow orange and red light : Additional pigments like carotenoids help in maximizing light absorption, explaining the varied colors in plants, especially seen during autumn.

Carotenoids : Pigments that absorb light mainly in the blue and green regions and reflect light in the yellow, orange, and red regions, contributing to the colors of many fruits and vegetables.

ds) absorb blue

carotenoids absorb blue and green light and reflect yellow orange and red light : Additional pigments like carotenoids help in maximizing light absorption, explaining the varied colors in plants, especially seen during autumn.

Carotenoids : Pigments that absorb light mainly in the blue and green regions and reflect light in the yellow, orange, and red regions, contributing to the colors of many fruits and vegetables.

and green light and refl

carotenoids absorb blue and green light and reflect yellow orange and red light : Additional pigments like carotenoids help in maximizing light absorption, explaining the varied colors in plants, especially seen during autumn.

Carotenoids : Pigments that absorb light mainly in the blue and green regions and reflect light in the yellow, orange, and red regions, contributing to the colors of many fruits and vegetables.

ect yello

carotenoids absorb blue and green light and reflect yellow orange and red light : Additional pigments like carotenoids help in maximizing light absorption, explaining the varied colors in plants, especially seen during autumn.

Carotenoids : Pigments that absorb light mainly in the blue and green regions and reflect light in the yellow, orange, and red regions, contributing to the colors of many fruits and vegetables.

w, orange, and red light.

carotenoids absorb blue and green light and reflect yellow orange and red light : Additional pigments like carotenoids help in maximizing light absorption, explaining the varied colors in plants, especially seen during autumn.

Carotenoids : Pigments that absorb light mainly in the blue and green regions and reflect light in the yellow, orange, and red regions, contributing to the colors of many fruits and vegetables.

Carotenoids give carrots and sweet potatoes their orange color.
Accessory pigments are the reason leaves change colors in
autumn. In green leaves, there is so much chloro

Chlorophyll : A green pigment found in chloroplasts that is responsible for the absorption of light to provide energy for photosynthesis.

phyll that it
masks the other pigments. In autumn, as trees prepare to lose
their leaves, the chlorophyll molecules break down, revealing
the colors of other pigments. The colors red, yellow, and
orange can be seen.
Reading Essentials Chapter 8 Cellular Energy
87
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88
Chapter 8 Cellular Energy Reading Essentials
Copyright © Glencoe/McGra

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

w-Hill,

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

a division of The McGraw-Hill Companies

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

, Inc.
How does electron transpor

Electron Transport System : A series of compounds that transfer electrons from electron donors to electron acceptors via redox reactions, and couples this electron transfer with the transfer of protons across a membrane.

t work?
Photosystem

Photosystem : A complex found in the thylakoid membranes of plants, algae, and cyanobacteria that is involved in capturing light to initiate the process of photosynthesis.

I and photosystem II are made of pigments
that absorb light and proteins that are important in light
reactions. They are in the t

thylakoids and grana are structures within chloroplasts : Thylakoids are flattened sac-like membranes arranged in stacks called grana, playing a critical role in capturing and converting light energy.

Thylakoid : A membrane-bound compartment inside chloroplasts, the site of the light-dependent reactions of photosynthesis.

Thylakoid Membrane : A membrane-bound compartment inside chloroplasts and cyanobacteria where the light-dependent reactions of photosynthesis take place.

hylak

thylakoids and grana are structures within chloroplasts : Thylakoids are flattened sac-like membranes arranged in stacks called grana, playing a critical role in capturing and converting light energy.

Thylakoid : A membrane-bound compartment inside chloroplasts, the site of the light-dependent reactions of photosynthesis.

Thylakoid Membrane : A membrane-bound compartment inside chloroplasts and cyanobacteria where the light-dependent reactions of photosynthesis take place.

oid membrane

thylakoids and grana are structures within chloroplasts : Thylakoids are flattened sac-like membranes arranged in stacks called grana, playing a critical role in capturing and converting light energy.

Thylakoid : A membrane-bound compartment inside chloroplasts, the site of the light-dependent reactions of photosynthesis.

Thylakoid Membrane : A membrane-bound compartment inside chloroplasts and cyanobacteria where the light-dependent reactions of photosynthesis take place.

. Follow
along in the fi gure below as you read about their role in
photosynthesis

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

.
Photosynthesis begins when light energ

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

y causes electrons in

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

photosystem II t

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

o go into a high energy state

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis begins when light energy causes electrons in photosystem II to go into a high energy state : Photosynthesis starts when photosystem II absorbs light energy, which excites electrons and sets off the process.

. The light ener

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

gy

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

also causes a water molecule to split,

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

releasing an electro

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

n
into the electron transport system

Electron Transport System : A series of compounds that transfer electrons from electron donors to electron acceptors via redox reactions, and couples this electron transfer with the transfer of protons across a membrane.

, a

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

hydrogen ion into the

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

thylakoid space, and oxygen as a waste pr

ATP is made when light energy causes the water molecule to split into oxygen and two hydrogen ions (H+) : The splitting of water molecules releases oxygen and hydrogen ions, leading to the production of ATP, an energy storage molecule.

oduct. The excited
electrons move from photosystem II and move along a series
of electron-carriers to photosystem I. Photosystem I absorbs
more light, and the excited electrons move along electron-
carriers again. Finally, the electrons are moved to NADP

NADPH : An electron carrier that provides high-energy electrons for the light-independent reactions of photosynthesis.

,
forming the energy-storage molecule NADPH.
How is ATP made during photosynthesis?
ATP is made when light energy causes the water molecule
to split into oxygen and two hydrogen ions (H), or protons.
Protons build up inside the thylak

Thylakoid : A membrane-bound compartment inside chloroplasts, the site of the light-dependent reactions of photosynthesis.

Thylakoid Membrane : A membrane-bound compartment inside chloroplasts and cyanobacteria where the light-dependent reactions of photosynthesis take place.

oid

Thylakoid : A membrane-bound compartment inside chloroplasts, the site of the light-dependent reactions of photosynthesis.

Thylakoid Membrane : A membrane-bound compartment inside chloroplasts and cyanobacteria where the light-dependent reactions of photosynthesis take place.

. Protons diffuse through
ion channels into the str

Stroma : The fluid-filled space surrounding the grana inside the chloroplast where the light-independent reactions of photosynthesis, or the Calvin cycle, take place.

oma where the concentration is lower.
These channels are enzymes called ATP synthases.

ATP Synthase : An enzyme that creates the energy storage molecule adenosine triphosphate (ATP) by combining adenosine diphosphate (ADP) with inorganic phosphate, using a flow of protons across the thylakoid membrane.

As protons
move into the stroma, ATP is formed.
5. Describe Of what
are photosystem

Photosystem : A complex found in the thylakoid membranes of plants, algae, and cyanobacteria that is involved in capturing light to initiate the process of photosynthesis.

I and
photosystem II made?
Picture This
6. Identify On the fi gure,
highlight the path that
electrons follow. What
molecule is the electrons
nal destination?
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FINALELECTRON
ACCEPTOR
!CTIVATED
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,IGHT
,IGHT
(
(
(
(
.!$0(
(
!$0
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En
En
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Copyright © Glencoe/McGra

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

w-Hill,

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

a division of The McGraw-Hill Companies

Glencoe/McGraw-Hill : A division of The McGraw-Hill Companies, Inc., which is a publishing company

The McGraw-Hill Companies, Inc. : A publishing company known for educational content

, Inc.
Phase Two: The Calvin Cycle

Calvin Cycle : Also known as the light-independent reactions, it is a set of chemical reactions that take place in chloroplasts during photosynthesis, using energy from ATP and NADPH to convert carbon dioxide into glucose.

NADPH and A

NADPH : An electron carrier that provides high-energy electrons for the light-independent reactions of photosynthesis.

TP are temporary storage molecules. During
phase two

The Calvin cycle builds sugars out of carbon dioxide and water using the energy stored in ATP and NADPH : In the Calvin cycle, carbon dioxide and water are converted into sugars, utilizing the energy stored in ATP and NADPH from the light-dependent reactions.

, also known as the Calvin cycle, the energy in these

The Calvin cycle builds sugars out of carbon dioxide and water using the energy stored in ATP and NADPH : In the Calvin cycle, carbon dioxide and water are converted into sugars, utilizing the energy stored in ATP and NADPH from the light-dependent reactions.

molecules is stor

The Calvin cycle builds sugars out of carbon dioxide and water using the energy stored in ATP and NADPH : In the Calvin cycle, carbon dioxide and water are converted into sugars, utilizing the energy stored in ATP and NADPH from the light-dependent reactions.

ed in organic molecules, such as glucose.
What happens in the Calvin cycle?
The Calvin cycle builds sugars out of carbon dioxide and
water using the energy stored in ATP and NADPH. The Calvin
cycles reactions do not r

Light-independent reactions : The second phase of photosynthesis, also known as the Calvin cycle, which takes place in the stroma of chloroplasts, using ATP and NADPH to synthesize glucose.

equire sunlight,

Light-independent reactions : The second phase of photosynthesis, also known as the Calvin cycle, which takes place in the stroma of chloroplasts, using ATP and NADPH to synthesize glucose.

which is why they ar

Light-independent reactions : The second phase of photosynthesis, also known as the Calvin cycle, which takes place in the stroma of chloroplasts, using ATP and NADPH to synthesize glucose.

e
also referred t

Light-independent reactions : The second phase of photosynthesis, also known as the Calvin cycle, which takes place in the stroma of chloroplasts, using ATP and NADPH to synthesize glucose.

o as light-independent

Light-independent reactions : The second phase of photosynthesis, also known as the Calvin cycle, which takes place in the stroma of chloroplasts, using ATP and NADPH to synthesize glucose.

reactions.
In the Calvin cycle, carbon dioxide molecules combine
with six 5-carbon compounds to make twelve 3-carbon
molecules. The chemical energy stored in ATP and NADPH
is passed to the 3-carbon molecules. Two 3-carbon molecules
leave the cycle to be used to make gluc

Glucose : A simple sugar produced during the Calvin Cycle that can be used as energy or for building complex carbohydrates.

ose

Glucose : A simple sugar produced during the Calvin Cycle that can be used as energy or for building complex carbohydrates.

and other organic
compounds. The enzyme rubisco

Rubisco : Ribulose-1,5-bisphosphate carboxylase/oxygenase, an enzyme involved in the first major step of carbon fixation in the Calvin cycle, considered one of the most important enzymes in the world.

changes ten 3-carbon
molecules into six 5-carbon molecules to continue the cycle.
Because rubisco changes carbon dioxide molecules into
organic molecules that can be used by the cell, it is considered
one of the most important enzymes. Sugar formed in the
Calvin cycle

Calvin Cycle : Also known as the light-independent reactions, it is a set of chemical reactions that take place in chloroplasts during photosynthesis, using energy from ATP and NADPH to convert carbon dioxide into glucose.

can be used as energy and as building blocks
for complex carbohydrates, such as starch.
Alternative Pathways

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

Photosynthesis might be diffi

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

cult for plants that grow in
hot, dry environments. Many plants in extreme climates have
evolved other photosynthesis pathways.
Tropical plants such as sugar cane and corn use the C4
path

C4 Pathway : A carbon fixation process found in certain plants that allows them to more efficiently photosynthesize in hot and dry environments by fixing carbon into 4-carbon molecules.

way. Instead of the 3-carbon molecules o

C4 plants fix carbon dioxide into 4-carbon molecules, losing less water : C4 plants use a unique pathway to fix carbon dioxide, resulting in reduced water loss, which is beneficial in hot and dry environments.

f the Calvi

C4 plants fix carbon dioxide into 4-carbon molecules, losing less water : C4 plants use a unique pathway to fix carbon dioxide, resulting in reduced water loss, which is beneficial in hot and dry environments.

n
cycle

Calvin Cycle : Also known as the light-independent reactions, it is a set of chemical reactions that take place in chloroplasts during photosynthesis, using energy from ATP and NADPH to convert carbon dioxide into glucose.

, C4 plants

C4 plants fix carbon dioxide into 4-carbon molecules, losing less water : C4 plants use a unique pathway to fix carbon dioxide, resulting in reduced water loss, which is beneficial in hot and dry environments.

x carbon dioxide int

C4 plants fix carbon dioxide into 4-carbon molecules, losing less water : C4 plants use a unique pathway to fix carbon dioxide, resulting in reduced water loss, which is beneficial in hot and dry environments.

o 4-carbon molecules.
Less water is lost in the C4 pathway. These plants keep their
stomata closed during hot days to minimize water loss.
What are CAM plants?
Another alternative pathwa

CAM Pathway : Crassulacean Acid Metabolism, an alternative photosynthetic process allowing plants in arid environments to fix carbon dioxide only at night to minimize water loss.

y is called the CAM

CAM Pathway : Crassulacean Acid Metabolism, an alternative photosynthetic process allowing plants in arid environments to fix carbon dioxide only at night to minimize water loss.

pathway.
CAM plants liv

CAM plants live in deserts, salt marshes, and environments with limited water : CAM plants have adapted to conserve water by capturing carbon dioxide at night and utilizing it during the day, allowing them to survive in arid conditions.

e in deserts, salt marshes,

CAM plants live in deserts, salt marshes, and environments with limited water : CAM plants have adapted to conserve water by capturing carbon dioxide at night and utilizing it during the day, allowing them to survive in arid conditions.

and other e

CAM plants live in deserts, salt marshes, and environments with limited water : CAM plants have adapted to conserve water by capturing carbon dioxide at night and utilizing it during the day, allowing them to survive in arid conditions.

nvironments

CAM plants live in deserts, salt marshes, and environments with limited water : CAM plants have adapted to conserve water by capturing carbon dioxide at night and utilizing it during the day, allowing them to survive in arid conditions.

where ac

CAM plants live in deserts, salt marshes, and environments with limited water : CAM plants have adapted to conserve water by capturing carbon dioxide at night and utilizing it during the day, allowing them to survive in arid conditions.

cess t

CAM plants live in deserts, salt marshes, and environments with limited water : CAM plants have adapted to conserve water by capturing carbon dioxide at night and utilizing it during the day, allowing them to survive in arid conditions.

o water is limited

CAM plants live in deserts, salt marshes, and environments with limited water : CAM plants have adapted to conserve water by capturing carbon dioxide at night and utilizing it during the day, allowing them to survive in arid conditions.

. Cac

Cacti : A group of spiky plants generally found in deserts that use the CAM pathway.

ti and orchi

Orchids : A diverse and widespread family of flowering plants, some of which utilize the CAM pathway.

ds are CAM
plants. Carbon dioxide enters the leaves of CAM plants only
at night, when the atmosphere is cooler and more humid.
The plants also fi x carbon dioxide into organic compounds at
night. During the day, carbon dioxide is released from organic
compounds in the plants. The carbon dioxide en

Calvin Cycle : Also known as the light-independent reactions, it is a set of chemical reactions that take place in chloroplasts during photosynthesis, using energy from ATP and NADPH to convert carbon dioxide into glucose.

The Calvin cycle builds sugars out of carbon dioxide and water using the energy stored in ATP and NADPH : In the Calvin cycle, carbon dioxide and water are converted into sugars, utilizing the energy stored in ATP and NADPH from the light-dependent reactions.

ters the Calvin

Calvin Cycle : Also known as the light-independent reactions, it is a set of chemical reactions that take place in chloroplasts during photosynthesis, using energy from ATP and NADPH to convert carbon dioxide into glucose.

The Calvin cycle builds sugars out of carbon dioxide and water using the energy stored in ATP and NADPH : In the Calvin cycle, carbon dioxide and water are converted into sugars, utilizing the energy stored in ATP and NADPH from the light-dependent reactions.

cycle

Calvin Cycle : Also known as the light-independent reactions, it is a set of chemical reactions that take place in chloroplasts during photosynthesis, using energy from ATP and NADPH to convert carbon dioxide into glucose.

The Calvin cycle builds sugars out of carbon dioxide and water using the energy stored in ATP and NADPH : In the Calvin cycle, carbon dioxide and water are converted into sugars, utilizing the energy stored in ATP and NADPH from the light-dependent reactions.

at that point. The CAM pat

CAM Pathway : Crassulacean Acid Metabolism, an alternative photosynthetic process allowing plants in arid environments to fix carbon dioxide only at night to minimize water loss.

hway minimizes water loss,
while allowing for adequate carbon uptake.
7. Nam

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

e the main energy

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

-
storing products of each

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

phase of photosynthesis

photosynthesis is the process in which light energy from the sun is changed into chemical energy : This process is crucial for converting solar energy into a form that can be utilized by living organisms, particularly in creating the food base for most ecosystems.

Photosynthesis : The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. Light energy from the Sun is converted into chemical energy in the form of glucose.

.
8. Name two places where
CAM plants live.
Reading Essentials Chapter 8 Cellular Energy
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