1. CHAPTER 8: PHOTOSYNTHESIS

2. 8-1 Energy of Life
Energy=
Living organisms depend on energy.
Living things get energy from _______.
The ultimate source of energy is the _____.
The ability to do work
food
sun

3. Autotrophs and Heterotrophs
Example: plants use sunlight to make food
Heterotrophs=
Example: ___________ eat plants
___________- eat animals that
have stored energy from
plants they eat
___________- eat dead
organisms
Organisms that make their own food
Organisms that need to consume
food for energy
herbivores
carnivores
decomposers

4. B. Chemical Energy and ATP
Forms of energy: light, heat, electricity, and
_____ (Adenosine Triphosphate)=
Section 8-1
Chemical energy (stored in bonds)
ATP
The basic energy source (chemical energy) of all cells
Adenine
Ribose
3 Phosphate groups

5. Storing Energy
ADP (Adenosine Diphosphate) contains ____ phosphates instead of 3.
If a cell has extra energy,
2. Releasing Energy
To release energy stored in ATP, 2
Small amounts can be stored by adding a
phosphate group to ADP molecules to produce ATP.
The cell can break the high energy bond between
the 2nd and 3rd phosphate group

6. Figure 8-3 Comparison of ADP and ATP to a Battery
Section 8-1
ADP
ATP
Energy
Energy
Adenosine diphosphate (ADP) + Phosphate
Adenosine triphosphate (ATP)
Partially
charged
battery
Fully
charged
battery

7. Using Biochemical Energy
How ATP is used in the cell -
Cells contain a small amount of ATP.
Only enough to provide a few seconds of activity.
ATP is great at ________________ but not good at
Glucose stores ___ times more energy than ATP.
The energy stored in Glucose can be used to
Carry out active transport
Aids in moving organelles throughout the cell
Protein synthesis
Producing light (ex. fireflies)
transferring energy
Storing large amounts of energy 90
regenerate ATP when the cell needs it.

8. 8-2 Photosynthesis: An Overview
Plants convert ______________ → ______________
through a series of oxidation/reduction reactions.
Process where plants use energy from sunlight
to convert water and carbon dioxide into
high-energy sugars and oxygen.
Sunlight energy
Chemical energy
6 CO2 + 6H2O SUNLIGHT C6H12O6 (SUGAR) + 6O2

9. 6 CO2 + 6H2O + SUNLIGHT C6H12O6 (SUGAR) + 6O2

10. Light Energy Chloroplast Sugars + O2 CO2 + H2O
Photosynthesis: Reactants and Products
Section 8-2
Light Energy
Chloroplast
Sugars + O2
CO2 + H2O

11. A. Investigating Photosynthesis
Investigations into photosynthesis began with the
following question:
“When a tiny seedling grows into
a tall tree with a mass of several tons,
where does the tree’s increase in mass come from?”

12. ______________ Experiment (1643)
Put soil in pot and took mass
Had seedling and took mass
Put seedling in soil...watered...waited five years...
the seedling became a tree.
He concluded that
He determined that
Van Helmont’s
                                          
the mass came from water
Plants need water to grow

13. ___________ Experiment (1771)
Put a lit candle in a bell jar-
Placed a mint plant in the jar with the candle-
Concluded
He determined
Priestly’s
The flame died out.
                                                            
Flame lasted longer
plants release a substance needed
for candle burning.
plants release oxygen

14. ________________Experiment (1779)
Put aquatic plants in light...
Put aquatic plants in dark...
He determined:
_______________ (1948)
He determined
Known as the
Jan Ingenhousz
produced oxygen
No oxygen
Light is needed to produce oxygen
Melvin Calvin
carbon’s path to make glucose
Calvin cycle

15. B. Light and Pigments
Photosynthesis requires ______ (soil), ____________ (air),
and ____ (sun), and ________ (a molecule in chloroplasts).
Energy from the sun is in the form of _____.
Sunlight= perceived as white light=
The wavelengths you can see are part of the
_______________.
Plants capture light with light absorbing molecules called
________.
The main pigment is chlorophyll (2 kinds)
water
Carbon dioxide
light
chlorophyll
light
A mixture of different
wavelengths
Visible Spectrum
pigments
Chlorophyll a
Chlorophyll b

16. Chlorophyll absorbs light in the __________ and ___ wavelengths
Blue-violet
Figure 8-5 Chlorophyll Light Absorption
red
Section 8-2
Absorption of Light by
Chlorophyll a and Chlorophyll b
Chlorophyll b
Chlorophyll a
Gamma rays
X-rays UV
Infrared
Micro- waves
Radio
waves
Visible light
Wavelength (nm) V B G Y O R

17. Chlorophyll reflects ______ wavelengths (that’s why
plants appear green)
The energy absorbed by chlorophyll is transferred to
_________ (in chloroplasts) which makes
photosynthesis work.
green
electrons

18. The location and structure of chloroplasts
LEAF CROSS SECTION
MESOPHYLL CELL
LEAF
Mesophyll
CHLOROPLAST
Intermembrane space
Outer
membrane
Granum
Inner membrane
Grana
Stroma
Thylakoid compartment
Stroma
Figure 7.2
Thylakoid

19. 8-3 The Reactions of Photosynthesis
A. Inside a Chloroplast
Site of Photosynthesis=
The chloroplasts
Reflected light
Light
Chloroplast
Absorbed light
Transmitted light

20. Photosynthesis is a two part process: -aka: 2.
Light-dependent reactions (located in thylakoid membranes)
Light Reaction
Light-independent reactions (located in stroma)
Dark reaction
Figure 8-7 Photosynthesis: An Overview
Calvin Cycle
Carbon fixation
H20
Light O2
Sugars
CO2
Chloroplast
Chloroplast
NADP+
ADP + P
Light-
Dependent
Reactions
Calvin
Cycle
ATP
NADPH

21. LIGHT REACTIONS (in grana) CALVIN CYCLE (in stroma)
An overview of photosynthesis
H2O
CO2
Chloroplast
Light
NADP+
ADP + P
LIGHT REACTIONS (in grana)
CALVIN CYCLE (in stroma)
ATP
Electrons
NADPH O2
Sugar
Figure 7.5

22. 2e- B. Electron Carriers Sunlight energy is transferred to
The electrons
High energy electrons require
ANALOGY: If you wanted to transfer hot pizza rolls from the oven you need a special carrier (oven mitt)
Electron carriers pass electrons from carrier to carrier
to carrier;
A Key electron carrier in photosynthesis is NADP+.
NADP →→
(electron carrier) (high energy electrons) (hydrogen ions) (energy storing compound)
When energy is needed, the
electrons in chlorophyll.
gain a lot of energy.
a special carrier
(molecule/compound).
Forming an electron transport chain.
2e- H+
NADPH
Covalent bonds of NADPH are broken to release
the high energy electrons.

23. Light-Dependent Reactions (Requires Light)
Light-Dependent Reactions (Requires Light) ·   Located in the ___________________________ ·   In the light reaction, ___________ is used to produce _____ and _______
thylakoid membrane
light energy
ATP
NADPH

24. Primary electron acceptor
Electron transport chain
Electron transport
Photons
PHOTOSYSTEM I
PHOTOSYSTEM II
Energy for synthesis of
by chemiosmosis

25. KEY PLAYERS IN LIGHT REACTION:
·    Photosystem I and II:
·    Electron carriers:
·    Water:
ATP Synthase:
Clusters of chlorophyll pigment
ADP and NADP+
Donates electrons
Enzyme (protein) that makes ATP

26. Primary electron acceptor
PHOTOSYSTEM
Photon
Reaction center
Pigment molecules of antenna
Figure 7.7C

27. Light Reaction Process:
Hydrogen
Ion Movement
Photosystem II
Chloroplast
ATP synthase
Inner
Thylakoid
Space
Thylakoid
Membrane
Stroma
Electron
Transport Chain
Photosystem I
ATP Formation

28. ELECTRON TRANSPORT CHAIN
The production of ATP in photosynthesis
Thylakoid compartment (high H+)
Light
Light
Thylakoid membrane
Antenna molecules
Stroma (low H+)
ELECTRON TRANSPORT CHAIN
PHOTOSYSTEM II
PHOTOSYSTEM I
ATP SYNTHASE
Figure 7.9

29. A. Photosystem II (PSII). Absorbs light to. 2H2O. e- =. O2 =. H+= B
A. Photosystem II (PSII) * Absorbs light to   2H2O     e- =   O2 =   H+= B. Electron Transport Chain * The light energy * The electrons get passed
split (break up) water molecules
→ 4H e- + O2
Donated to chlorophyll
Released into air providing oxygen for us
Released inside the thylakoid membrane
excites electrons increasing
their energy level.
down an electron transport chain to
photosystem I (PSI)

30. C. Photosystem I. · Light energy energizes electrons
C. Photosystem I ·        Light energy energizes electrons. ·        NADP+ accepts the electrons and an H+ and becomes _________.   D. Hydrogen Ion Movement ·        When water splits, ·        The difference in concentration and charge   E. ATP Formation ·        _____ do not cross the membrane directly They need the help of a membrane protein. ·        H+ ions pass through the protein:
NADPH
H+ ions fill up the inner thylakoid space
(making it positively charged). As a result, the
stroma is negatively charged.
Provides the energy to make ATP.
Ions
ATP synthase - an enzyme that converts ADP to ATP

31. PRODUCTS OF THE LIGHT REACTION: ·   ____ : Released in the air ·  ______________: Contain a lot of chemical energy but cannot store it for long. So, they are used to power the dark reaction to _________________ which can store the energy for longer periods of time. O2
ATP & NADPH
help build glucose

32. Stroma with or without light.
Section 8-3 D. The Calvin Cycle (dark reaction; light independent) * Occurs in the
Figure 8-11 Calvin Cycle
Stroma with or without light.
CO2 Enters the Cycle
Energy Input
ChloropIast
5-Carbon
Molecules
Regenerated
6-Carbon Sugar
Produced
Sugars and other compounds

33. DARK REACTION PROCESS:
A. CO2 enters the system
            
 product=
B. Energy input
The _________________________________ are used to
C. 6-Carbon Sugar is produced
___ of the 12 3-C are used to make glucose and
other compounds.
D. 5-Carbon Molecules Regenerated
___ remaining 3-C are converted into 6 5-C molecules
6 CO2 combines with 6 5-C compounds
12 3-C compounds
ATP & NADPH (from the light reaction)
convert the 12 3-C compounds into a higher energy form. 2 10

34. PRODUCTS OF THE CALVIN CYCLE (DARK REACTION):. E
PRODUCTS OF THE CALVIN CYCLE (DARK REACTION): *                      E. Factors Affecting Photosynthesis *          *   Plants often have a ______ coating to protect against dehydration *         * The greater the _____________, the better photosynthesis functions (up to a point).
High Energy Sugars
Shortage of water can stop/slow down photosynthesis
waxy
Very low/high temperatures (damages enzymes) can
stop/slow down photosynthesis (optimal temp.= 0°– 35° C
Light intensity

35. Concept Map Photosynthesis Light- dependent reactions Calvin cycle
Section 8-3
Photosynthesis
includes
Light-
dependent
reactions
Calvin cycle
takes place in
uses
use
take place in
Thylakoid
membranes
Stroma
NADPH
ATP
Energy from
sunlight
to produce of
to produce
ATP
NADPH O2
Chloroplasts
High-energy
sugars