Fill in the Blanks
Photosynthesis for the biology CLEP examOnline version
everything here can be found on Modern States' Biology course.
is
the
only
biological
process
that
can
capture
energy
that
originates
in
outer
space
(
)
and
convert
it
into
chemical
compounds
(
)
that
every
organism
uses
to
power
its
.
The
energy
of
is
captured
and
used
to
energize
,
which
are
then
stored
in
the
bonds
of
molecules
.
Plants
,
algae
,
and
a
group
of
bacteria
called
are
the
only
organisms
capable
of
performing
.
Because
they
use
light
to
manufacture
their
own
food
,
they
are
called
(
literally
,
"
self
-
feeders
using
light
"
)
.
Other
organisms
,
such
as
animals
,
fungi
,
and
most
other
bacteria
,
are
termed
(
"
other
feeders
"
)
,
because
they
must
rely
on
the
sugars
produced
by
organisms
for
their
energy
needs
.
A
third
very
interesting
group
of
bacteria
synthesize
sugars
,
not
by
using
sunlight
?
s
energy
,
but
by
extracting
energy
from
chemical
compounds
;
hence
,
they
are
referred
to
as
.
is
vital
because
it
evolved
as
a
way
to
the
energy
in
radiation
(
the
"
photo
-
"
part
)
as
high
-
energy
in
the
carbon
-
bonds
of
molecules
(
the
"
-
synthesis
"
part
)
.
Those
carbohydrates
are
the
energy
source
that
use
to
power
the
synthesis
of
via
.
Therefore
,
photosynthesis
powers
99
percent
of
Earth
?
s
ecosystems
.
When
a
top
predator
,
such
as
a
wolf
,
preys
on
a
deer
,
the
wolf
is
at
the
of
an
energy
path
that
went
from
reactions
on
the
surface
of
the
sun
,
to
,
to
,
to
,
to
,
and
finally
to
.
is
a
multi
-
step
process
that
requires
,
(
which
is
low
in
energy
)
,
and
as
(
Figure
8
.
4
)
.
After
the
process
is
complete
,
it
releases
and
produces
glyceraldehyde
-
3
-
phosphate
(
)
,
simple
carbohydrate
molecules
(
which
are
high
in
energy
)
that
can
subsequently
be
converted
into
,
,
or
any
of
dozens
of
other
sugar
molecules
.
These
sugar
molecules
contain
energy
and
the
energized
carbon
that
all
living
things
need
to
survive
.
The
basic
equation
for
is
deceptively
simple
.
In
reality
,
the
process
takes
place
in
many
steps
involving
intermediate
and
.
,
the
primary
energy
source
in
,
is
made
from
two
-
carbon
GA3Ps
.
In
plants
,
generally
takes
place
in
,
which
consist
of
several
layers
of
.
The
process
of
photosynthesis
occurs
in
a
middle
layer
called
the
.
The
gas
exchange
of
carbon
dioxide
and
oxygen
occurs
through
small
,
regulated
openings
called
(
singular
:
stoma
)
,
which
also
play
roles
in
the
regulation
of
gas
exchange
and
water
balance
.
The
are
typically
located
on
the
underside
of
the
leaf
,
which
helps
to
minimize
water
loss
.
Each
is
flanked
by
cells
that
regulate
the
opening
and
closing
of
the
by
swelling
or
shrinking
in
response
to
changes
.
In
all
eukaryotes
,
photosynthesis
takes
place
inside
an
organelle
called
a
.
For
plants
,
chloroplast
-
containing
cells
exist
in
the
.
Chloroplasts
have
a
membrane
envelope
(
composed
of
an
outer
membrane
and
an
inner
membrane
)
.
Within
the
chloroplast
are
stacked
,
disc
-
shaped
structures
called
.
Embedded
in
the
thylakoid
membrane
is
,
a
pigment
(
molecule
that
absorbs
light
)
responsible
for
the
initial
interaction
between
and
plant
material
,
and
numerous
that
make
up
the
.
The
thylakoid
membrane
encloses
an
internal
space
called
the
.
A
stack
of
thylakoids
is
called
a
,
and
the
liquid
-
filled
space
surrounding
the
granum
is
called
or
"
bed
"
(
not
to
be
confused
with
or
"
mouth
,
"
an
opening
on
the
leaf
epidermis
)
.
takes
place
in
,
which
have
an
membrane
and
an
membrane
.
Stacks
of
thylakoids
called
form
a
membrane
layer
.
takes
place
in
sequential
stages
:
the
light
-
dependent
reactions
and
the
light
independent
-
reactions
.
In
the
,
energy
from
sunlight
is
absorbed
by
chlorophyll
and
that
energy
is
converted
into
stored
chemical
energy
.
In
the
,
the
chemical
energy
harvested
during
the
light
-
dependent
reactions
drive
the
assembly
of
molecules
from
carbon
dioxide
.
Therefore
,
although
the
light
-
independent
reactions
do
not
use
as
a
reactant
,
they
require
the
products
of
the
light
-
dependent
reactions
to
function
.
In
addition
,
several
enzymes
of
the
light
-
independent
reactions
are
activated
by
.
The
light
-
dependent
reactions
utilize
certain
molecules
to
temporarily
store
the
energy
:
These
are
referred
to
as
.
The
energy
carriers
that
move
energy
from
light
-
dependent
reactions
to
light
-
independent
reactions
can
be
thought
of
as
"
full
"
because
they
are
rich
in
energy
.
After
the
energy
is
released
,
the
"
empty
"
energy
carriers
return
to
the
light
-
reaction
to
obtain
more
energy
.
takes
place
in
two
stages
:
light
reactions
and
the
.
Light
-
dependent
reactions
,
which
take
place
in
the
membrane
,
use
light
energy
to
make
and
.
The
Calvin
cycle
,
which
takes
place
in
the
,
uses
energy
derived
from
these
compounds
to
make
from
.
The
sun
emits
an
enormous
amount
of
(
solar
energy
)
.
Humans
can
see
only
a
fraction
of
this
energy
,
which
portion
is
therefore
referred
to
as
"
visible
The
manner
in
which
solar
energy
travels
is
described
as
.
Scientists
can
determine
the
amount
of
energy
of
a
wave
by
measuring
its
,
the
distance
between
consecutive
points
of
a
wave
.
A
single
wave
is
measured
from
consecutive
points
,
such
as
from
crest
to
crest
or
from
trough
to
trough
.
Visible
light
constitutes
only
one
of
many
types
of
emitted
from
the
sun
and
other
stars
.
Scientists
differentiate
the
various
types
of
energy
from
the
sun
within
the
.
The
is
the
range
of
all
possible
frequencies
of
radiation
.
The
difference
between
wavelengths
relates
to
the
amount
of
carried
by
them
.
Each
type
of
travels
at
a
particular
wavelength
.
The
longer
the
wavelength
(
or
the
more
stretched
out
it
appears
in
the
diagram
)
,
energy
is
carried
.
Short
,
tight
waves
carry
energy
.
This
may
seem
illogical
,
but
think
of
it
in
terms
of
a
piece
of
moving
a
heavy
rope
.
It
takes
little
effort
by
a
person
to
move
a
rope
in
long
,
wide
waves
.
To
make
a
rope
move
in
short
,
tight
waves
,
a
person
would
need
to
apply
significantly
more
energy
.
The
shows
several
types
of
originating
from
the
,
including
and
.
The
higher
-
energy
waves
can
penetrate
tissues
and
damage
,
explaining
why
both
X
-
rays
and
UV
rays
can
be
harmful
to
living
organisms
.
initiates
the
process
of
when
absorb
the
.
pigments
,
whether
in
the
human
retina
or
the
chloroplast
thylakoid
,
have
a
range
of
energy
levels
that
they
can
absorb
.
Energy
levels
lower
than
those
represented
by
are
insufficient
to
raise
an
to
a
populatable
,
excited
(
quantum
)
state
.
Energy
levels
higher
than
those
in
will
physically
tear
the
molecules
apart
,
called
.
So
retinal
pigments
can
only
"
see
"
(
absorb
)
to
light
,
which
is
therefore
called
.
For
the
same
reasons
,
pigment
molecules
absorb
only
light
in
the
wavelength
range
of
to
;
plant
physiologists
refer
to
this
range
for
plants
as
.
The
visible
light
seen
by
humans
as
actually
exists
in
a
rainbow
of
colors
.
Certain
objects
,
such
as
a
prism
or
a
drop
of
water
,
disperse
white
light
to
reveal
the
colors
to
the
human
eye
.
The
visible
light
portion
of
the
shows
the
rainbow
of
colors
,
with
and
having
wavelengths
,
and
therefore
energy
.
At
the
other
end
of
the
spectrum
toward
,
the
wavelengths
are
and
have
energy
.
Different
kinds
of
pigments
exist
,
and
each
has
evolved
to
absorb
only
certain
wavelengths
(
colors
)
of
.
reflect
or
transmit
the
wavelengths
they
cannot
absorb
,
making
them
appear
in
the
corresponding
color
.
and
are
the
two
major
classes
of
photosynthetic
pigments
found
in
and
;
each
class
has
multiple
types
of
pigment
molecules
.
There
are
five
major
chlorophylls
:
and
a
related
molecule
found
in
prokaryotes
called
.
With
dozens
of
different
forms
,
are
a
much
larger
group
of
pigments
.
The
found
in
fruit
?
such
as
the
red
of
tomato
(
lycopene
)
,
the
yellow
of
corn
seeds
(
zeaxanthin
)
,
or
the
orange
of
an
orange
peel
(
?
-
carotene
)
?
are
used
as
advertisements
to
attract
seed
dispersers
.
In
photosynthesis
,
function
as
photosynthetic
pigments
that
are
very
efficient
molecules
for
the
disposal
of
excess
energy
.
When
a
leaf
is
exposed
to
full
sun
,
the
are
required
to
process
an
enormous
amount
of
energy
;
if
that
energy
is
not
handled
properly
,
it
can
do
significant
damage
.
Therefore
,
many
reside
in
the
,
absorb
excess
energy
,
and
safely
dissipate
that
energy
as
.
Each
type
of
pigment
can
be
identified
by
the
specific
pattern
of
it
absorbs
from
visible
light
,
which
is
the
.
Chlorophyll
absorbs
wavelengths
from
either
end
of
the
visible
spectrum
(
blue
and
red
)
,
but
not
.
Because
green
is
reflected
or
transmitted
,
chlorophyll
appears
green
.
absorb
in
the
region
,
and
reflect
the
longer
yellow
,
red
,
and
orange
wavelengths
.
Chlorophyll
a
,
chlorophyll
b
,
and
?
-
carotene
are
found
in
the
.
Chlorophyll
a
and
b
are
responsible
for
the
color
of
leaves
.
?
-
is
responsible
for
the
orange
color
in
carrots
.
Each
pigment
has
a
unique
absorbance
.
When
studying
a
,
scientists
can
determine
the
types
of
pigments
present
by
generating
.
An
instrument
called
a
can
differentiate
which
wavelengths
of
light
a
substance
can
absorb
.
measure
transmitted
light
and
compute
from
it
the
absorption
.
By
extracting
from
leaves
and
placing
these
samples
into
a
,
scientists
can
identify
which
wavelengths
of
light
an
organism
can
absorb
.
Additional
methods
for
the
identification
of
plant
pigments
include
various
types
of
that
separate
the
pigments
by
their
relative
affinities
to
solid
and
mobile
phases
.
The
overall
function
of
is
to
convert
solar
energy
into
chemical
energy
in
the
form
of
and
.
This
chemical
energy
supports
the
and
fuels
the
assembly
of
.
complexes
and
work
together
to
produce
and
.
The
actual
step
that
converts
light
energy
into
chemical
energy
takes
place
in
a
multiprotein
complex
called
a
,
two
types
of
which
are
found
embedded
in
the
,
(
PSII
)
and
(
PSI
)
.
The
two
complexes
differ
on
the
basis
of
what
they
oxidize
(
that
is
,
the
source
of
the
supply
)
and
what
they
reduce
(
the
place
to
which
they
deliver
their
)
.
Both
photosystems
have
the
same
basic
structure
;
a
number
of
to
which
the
chlorophyll
molecules
are
bound
surround
the
where
the
photochemistry
takes
place
.
Each
photosystem
is
serviced
by
the
,
which
passes
energy
from
sunlight
to
the
reaction
center
;
it
consists
of
multiple
that
contain
a
mixture
of
300
?
400
chlorophyll
a
and
b
molecules
as
well
as
other
pigments
like
.
The
absorption
of
a
single
or
distinct
quantity
or
"
packet
"
of
light
by
any
of
the
chlorophylls
pushes
that
molecule
into
an
excited
state
.
In
short
,
the
light
energy
has
now
been
captured
by
but
is
not
stored
in
any
useful
form
yet
.
The
energy
is
transferred
from
chlorophyll
to
chlorophyll
until
eventually
(
after
about
a
millionth
of
a
second
)
,
it
is
delivered
to
the
.
Up
to
this
point
,
only
energy
has
been
transferred
between
,
not
.
The
contains
a
pair
of
molecules
with
a
special
property
.
Those
two
chlorophylls
can
undergo
oxidation
upon
;
they
can
actually
give
up
an
electron
in
a
process
called
a
.
It
is
at
this
step
in
the
reaction
center
,
this
step
in
photosynthesis
,
that
light
energy
is
converted
into
an
electron
.
All
of
the
subsequent
steps
involve
getting
that
electron
onto
the
energy
carrier
for
delivery
to
the
where
the
electron
is
deposited
onto
carbon
for
long
-
term
storage
in
the
form
of
a
.
PSII
and
PSI
are
two
major
components
of
the
,
which
also
includes
the
.
The
,
an
enzyme
composed
of
two
protein
complexes
,
transfers
the
electrons
from
the
carrier
molecule
(
Pq
)
to
the
protein
(
Pc
)
,
thus
enabling
both
the
transfer
of
protons
across
the
and
the
transfer
of
electrons
from
to
.
The
reaction
center
of
PSII
(
called
)
delivers
its
high
-
energy
electrons
,
one
at
a
time
,
to
the
,
and
through
the
(
to
to
)
to
.
P680
?
s
missing
electron
is
replaced
by
extracting
a
from
;
thus
,
water
is
split
and
PSII
is
re
-
reduced
after
every
photoact
.
Splitting
one
H2O
molecule
releases
two
electrons
,
two
atoms
,
and
one
atom
of
.
Splitting
two
molecules
is
required
to
form
one
molecule
of
O2
gas
.
About
percent
of
the
oxygen
is
used
by
in
the
leaf
to
support
.
The
remainder
escapes
to
the
atmosphere
where
it
is
used
by
to
support
respiration
.
As
electrons
move
through
the
proteins
that
reside
between
PSII
and
PSI
,
they
energy
.
That
energy
is
used
to
move
from
the
side
of
the
membrane
to
the
.
Those
hydrogen
atoms
,
plus
the
ones
produced
by
splitting
,
accumulate
in
the
and
will
be
used
synthesize
ATP
in
a
later
step
.
Because
the
electrons
have
energy
prior
to
their
arrival
at
PSI
,
they
must
be
re
-
energized
by
PSI
,
hence
,
another
photon
is
absorbed
by
the
.
That
energy
is
relayed
to
the
PSI
reaction
center
(
called
)
.
is
oxidized
and
sends
a
high
-
energy
electron
to
+
to
form
.
Thus
,
PSII
captures
the
energy
to
create
to
make
,
and
PSI
captures
the
energy
to
reduce
NADP
+
into
.
The
two
photosystems
work
in
concert
,
in
part
,
to
guarantee
that
the
production
of
will
roughly
equal
the
production
of
.
Other
mechanisms
exist
to
fine
tune
that
ratio
to
exactly
match
the
chloroplast
?
s
constantly
changing
energy
needs
.
As
in
the
intermembrane
space
of
the
during
cellular
respiration
,
the
buildup
of
inside
the
creates
a
concentration
gradient
.
The
diffusion
of
hydrogen
ions
from
high
concentration
(
in
the
thylakoid
lumen
)
to
low
concentration
(
in
the
stroma
)
is
harnessed
to
create
,
just
as
in
the
electron
transport
chain
of
cellular
respiration
.
The
ions
build
up
energy
because
of
and
because
they
all
have
the
same
electrical
charge
,
repelling
each
other
.
To
release
this
energy
,
will
rush
through
any
opening
,
similar
to
water
jetting
through
a
hole
in
a
dam
.
In
the
thylakoid
,
that
opening
is
a
passage
through
a
specialized
protein
channel
called
the
.
The
energy
released
by
the
stream
allows
to
attach
a
third
group
to
,
which
forms
a
molecule
of
.
The
flow
of
hydrogen
ions
through
ATP
synthase
is
called
because
the
ions
move
from
an
area
of
high
to
an
area
of
low
concentration
through
a
.
After
the
energy
from
the
sun
is
converted
into
chemical
energy
and
temporarily
stored
in
and
molecules
,
the
cell
has
the
fuel
needed
to
build
for
long
-
term
energy
storage
.
The
products
of
the
,
ATP
and
NADPH
,
have
lifespans
in
the
range
of
millionths
of
seconds
,
whereas
the
products
of
the
(
carbohydrates
and
other
forms
of
reduced
carbon
)
can
survive
for
hundreds
of
millions
of
years
.
The
carbohydrate
molecules
made
will
have
a
backbone
of
.
Where
does
the
carbon
come
from
?
It
comes
from
,
the
gas
that
is
a
waste
product
of
respiration
in
microbes
,
fungi
,
plants
,
and
animals
.
In
plants
,
carbon
dioxide
(
CO2
)
enters
the
leaves
through
,
where
it
diffuses
over
short
distances
through
until
it
reaches
the
cells
.
Once
in
the
cells
,
diffuses
into
the
of
the
chloroplast
?
the
site
of
light
-
reactions
of
photosynthesis
.
These
reactions
actually
have
several
names
associated
with
them
.
Another
term
,
the
,
is
named
for
the
man
who
discovered
it
,
and
because
these
reactions
function
as
a
cycle
.
Others
call
it
the
Calvin
-
Benson
cycle
to
include
the
name
of
another
scientist
involved
in
its
discovery
.
The
most
outdated
name
is
dark
reactions
,
because
is
not
directly
required
.
However
,
the
term
dark
reaction
can
be
misleading
because
it
implies
incorrectly
that
the
reaction
only
occurs
at
night
or
is
independent
of
light
,
which
is
why
most
scientists
and
instructors
no
longer
use
it
.
The
light
-
reactions
of
the
Calvin
cycle
can
be
organized
into
three
basic
stages
:
,
,
and
.
In
the
,
in
addition
to
,
two
other
components
are
present
to
initiate
the
light
-
reactions
:
an
enzyme
called
ribulose
-
1
,
5
-
bisphosphate
carboxylase
/
oxygenase
(
)
,
and
three
molecules
of
ribulose
bisphosphate
(
)
.
has
atoms
of
carbon
,
flanked
by
two
.
|
Complete the lyrics of the song with the words that appear on the right side
Fill in the missing words in this quiz concerning the Anatomy page of the website. You should read through the passage provided, and click the word you think fits from the list at the side. If you ...