Photosynthesis
Lesson 1
Outcomes
1. Explain how energy is absorbed by pigments, transferred through the reduction of
NADP+ to NADPH, and then transferred as chemical potential energy to ATP by
chemiosmosis
2. Explain how NADPH and ATP are used to reduce carbon in the light independent
reactions for the production of glucose
3. Identify where in the chloroplast these steps occur
ATP
What is ATP?
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
Universal ______________ molecule
Energy in a form the cell can use
Makes energy readily _________________
Continuously being remade
Stands for ___________________ _________________________
Uses of ATP
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

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_______________
___________________ of ions and molecules
________________molecules
Switching ______________ on or off
Redox Reactions
 Redox reactions (__________________-________________ reactions happen
throughout photosynthesis as _______________ get transferred from one molecule to
another.
 There are a couple of ways to remember what happens to the electron
o OIL RIG (_________________ is _____________, _______________ is
_________________)
o ______ goes _______ (lose electrons=oxidation, gain electrons=reduction)
 This is just a _____________ _______________ of gaining electrons (___) and passing
them to the next compound.
Photosynthesis
 The process of storing __________ energy (photons) as ____________ energy
(carbohydrates) in the cell.
 The equation:
Photosynthesis occurs in _____________________
Chloroplast parts
 ______________
o I disk
o Granum = a stack of disks
o Grana = plural granum (many stacks of disks)
o Site of the light dependent reaction (holds the ______________)
 ____________
o Gel surrounding the thylakoids
o Site of the light independent reaction
Chlorophyll
 A ___________ chemical that traps sunlight energy
 Located in the __________ of a chloroplast
 The ___________ chlorophyll a and chlorophyll b absorb light wavelengths on the _____
and ______ ends of the spectrum
 They ____________ green light, that’s why plants look green.
Pigments
 Leaves contain other light _______________ pigments (chemicals) besides chlorophyll
o Carotenoids (including carotene which reflects orange light, xanthophyll which
reflects yellow light, and lycopene which reflects red light)
o Flavonoids (more yellow reflecting pigments, and anthocyanin which reflects
shades of red, blue, and purple)
 Different plants have different _____________________ of these chemicals
 In the fall, chlorophylls begin to break down, and the other reflected colours begin to
________ through with the green to overpower them.
Lesson 1 Formative
Do the following questions and send them to me to check for understanding.
Pg 181 #2, pg 182 #4, pg 185 #4
Lesson 2
Photosynthesis
 There are two main parts to photosynthesis
o ________ ____________________ _______________

Needs light, therefore it takes place in the thylakoid _______________
where the chlorophyll is
 Takes in ________ and creates oxygen as a _____________.
 Creates intermediary (not _______) products of _______ and ________
for the Calvin Cycle.
o _________ ___________________ _______________
 Doesn’t need ________ so it happens outside the thylakoid in the
_________
 Also referred to as the _________ reactions (misleading because it
doesn’t only happen in the dark)
 Takes in _____ and _______ and ___________ from the thylakoid to
make __________ in a process called the Calvin Cycle.
Light Dependent Reaction
 All of these steps are happening at the same time, but for simplicity’s sake, we will learn
them separately.
1. Photosystem II (PSII)
o PSII is a group of chlorophyll pigments located on the ___________
___________.
o It absorbs the ____________ energy, transforming it into chemical energy in the
form of excited electrons ( )
o These
are unstable and ________ the chlorophyll, attaching to molecules in
the _________ (Electron Transport Chain)
o The chlorophyll loses its electrons so it is _____________ (remember LEO)
2. Photolysis
o In order to replace the electrons lost from the chlorophyll, a _______ molecule
will be split apart.
o ___________ energy is used to split H2O into its parts
 The __________ now leaves the thylakoid and the chloroplast and goes
into the air for us to breathe
 The H splits into its H+ and its electron (e-)
 The e- goes to the _____________ to replace the
it lost
 The chlorophyll has gained more electrons, therefore it has been
____________
3. Electron Transport Chain (ETC)
o The
from the PSII are transferred through the _______ like a bucket
o
o
o
o
o
o
o
brigade (one molecule ___________ it, and then passes it onto the next
molecule)
This is a series of ________ ___________, as the molecule that accepts the
is being ____________, but then is oxidized when it passes the
onto the
next molecule
When the _____ are being transferred, some of their _________ is used to take
H+ that are floating around in the stroma and ________ them into the thylakoid
________
The pumping of H+ into the thylakoid is an example of _______ _____________
This means it is using _____________ from the
and the movement is
against the concentration gradient
 The H+ are being pumped from an area of ______ concentration to an
area of ________ concentration
Building up a H+ concentration gradient means that the ________ of the
thylakoid is more ______________ charged than the stroma.
This is a form of ________________ energy (electrochemical gradient)
The
_______ their excess energy as they are transferred in the ETC until
they reach Photosystem I (PSI)
4. Reduction of NADP+
o When the low energy e- reaches PSI it gets __________ by the sun (e- into
o It leaves the ___________ at PSI and joins with ____ and _________ (floating
)
around waiting to be reduced) in the stroma to make __________
o NADPH is an electron __________. It moves the
and its H+ from the
thylakoid to the ____________ __________.
5. Chemiosmosis
o This is the process of making ATP using the potential electrochemical energy
o
o
o
o
from the H+ __________________ ____________________
The _____ concentration has built up in the ____________ lumen thanks to the
active transport of H+ inside by the ETC.
The _________ concentration of H+ means that they want to ___________ out in
order to achieve ____________________.
The H+ diffuse across the membrane because they are ______________, so they
must use a protein channel (facilitated diffusion)
The protein channel they diffuse out through is called the _______
______________ _______________.
o As the H+ _________________ through the ATP synthase channel, the structure
turns the potential energy (from H+ gradient) into ___________ energy that
turns the protein channel
o This kinetic energy is then transferred to the ____________ bond between ADP
and P to make the energy rich compound _____
Light Independent Reaction
 This takes place in the _________ of the chloroplast
 It is also called the ____________ ___________
 In this step, the CO2 from the air is bonded to the
and the H+ from NADPH to make
glucose (___________) – Carbon Fixation
o Oxidizing NADPH back into NADP+
 ATP donates its _____________ chemical energy to bond the C, H, and O together by
_____________ apart into ADP and P.
 Now you have the final product of ______________
 And the ADP, P, and NADP+ can go back to the ___________ to be used in the Light
Dependent Reactions again.
o They continue to cycle back and forth between the main stages
Summary
 Light energy is absorbed by __________________ and turned into chemical energy by
exciting electrons
 Water is ______________ apart to replace lost e- in PSII
 The electrons’ energy is used to create a ____ ___________________ ______________
(electrochemical potential energy now) in the ETC
 This gradient in turn transfers the energy into ____________ chemical energy in the ATP
molecule when H+ ___________ through the ATP Synthase Complex
 The electrons absorb more ______________ energy and are carried from the thylakoid
to the Calvin Cycle by _________
 The energy from _______ bonds the e- and H+ from NADPH to the CO2 to make C6H12O6
Lesson 2 Formative
Do the following questions for practice to see where you need to review more.
Pg 187 #1-3, pg 188 #4-6, pg 190 # 7-10, pg 191 #11-14, pg 193 #15-16
Then create a summary of photosynthesis from the perspective of an electron. You can write a
story, song, poem, etc., you can draw it out like a comic book or poster, or you can make a
computer animation…whatever format you want. Send the summary to me before you write
your test so that I can see if you understand the process.