1. The function and Structure of Chloroplasts Photosynthesis

2. I. Introduction to
Photosynthesis

3. A. Photosynthesis: capturing and transforming energy from sunlight into chemical energy (glucose)
* A process utilized by green
plants and blue-green algae,
and some Protozoan.
* These organisms are called
Autotrophs meaning they can
make their own food with light

4. Photosynthesis takes place in plants in the leaves only:
Chloroplasts
are here
Cross- section of a leaf

5. B. Sunlight is a form of radiation or energy in the form of waves.
This energy is absorbed by autotrophs in
The chloroplasts

6. C. Structure of the Chloroplast
Stroma
Thylacoid
Grana
Transmission electron micrograph

7. a. Thylacoid – sacs of membranes
with a coin-like shape.
- location of chlorophyll
- location of light reaction
b. Grana – stacks of thylacoids
c. Stroma – regions between the
grana.
-fluid-like region
-location of dark reactions when
organic molecules are made.

8. D. Pigments
*substance that absorb light
energy.
* Pigments use visible light- light
we can detect.
* When we “see” a color, that
wavelength of light is reflected
from the object. Others are
absorbed.

9. absorbed
red
reflected

10. What is the significance of plants Being green?
Plant REFLECT green light and absorb
others.

11. Plants contain several pigments, but the major pigment that absorbs
energy is called Chlorophyll
Polar- magnesium
“head”
Non –polar Lipid
“tail”

12. The other pigments plants contain
are called accessory pigments, pigments
that assist in the reactions of
photosynthesis.
Beta Carotene- yellow orange
Phycoerythrin- red
Xanthophyll- yellow

13. Chromotography
It is possible to extract, separate, and
analyze pigment from a plant. This
process is called Chromotography.
* Pigments are separated on paper
dependent on how soluble they are
in a particular solvent.
* Small molecules move fast, larger
molecules slower.
*Solvent moves across the paper
due to capillary action.

14. Plant pigment placed on paper. Solvent moves through paper due
To capillary action
Separating pigments

15. Alcohols: isopropanol, methanol Organic acids: acetone, hexane
What solvent would you use based
on the composition of chlorophyll?
Something non-polar:
Alcohols: isopropanol, methanol
Organic acids: acetone, hexane
* Not water!

16. II. The reactions of Photosynthesis

17. A. General equation for photosynthesis
6 CO2 + 6 H2O C6H12O6 + 6O2
Sunlight
enzymes
ATP
glucose
oxygen
water
Carbon dioxide
Many reactions are involved , this is the
Overall outcome.

18. Quick Overview
Two types of reactions in photosynthesis:
Light and Dark Reactions

19. B. The Light reactions require light and are also called the Light Dependent Reactions
* Need light and occur
during the day
*Take place in the grana of
the chloroplast
*Uses the energy from the
sun to break apart water
and ultimately produce
organic compounds.

20. (this is splitting water!)
1. Part 1: Photosystem II
*Light is absorbed and
excites electrons
*Electrons pass to the electron transport chain
*Makes ATP
*Takes electrons from H2O ( to replace those
lost)and forms O2 which is
released
(this is splitting water!)

21. *ATP is adenosine triphosphate, a
high energy molecule
*Oxygen is released through the
stomates ( openings on the under
surface of leaves)

22. 2. Part 2: Photosystem I
*More light is absorbed
*NADP forms NADPH (it is a protein that is a
hydrogen/electron acceptor,
like a shuttle to carry the
excited electrons)
* ATP and the “shuttle” move to
the Dark reaction.

25. Summary of Light Reactions
A. Electons are excited
B. Break apart water
C. Releases O2
D. Forms ATP and NADPH2

26. C. The second part of photosynthesis does not require light
C. The second part of photosynthesis does not require light. This is called the Dark or Light Independent Rection.
Electrons go through the Calvin Cycle:
*It starts with RuBP, a five carbon sugar that takes in CO2.
*Breaks ATP into ADP for energy
*Changes NADPH2 into NADP-
electrons dropped off the “shuttle”

27. *One glucose molecule is produced per 2 trips of the cycle
Beginning
ATP
NADPH2
from light
reaction
Calvin cycle
Summary of two
trips

28. Summary of the Dark Reactions
A. Use CO2
B. Change ATP into ADP
C. Change NADPH2 to NADP
D. Create glucose (stored as
cellulose or starch) and
other organic compounds

31. Location in chloroplast
You do this:
Reaction
Location in chloroplast
Reactants necessary
Products produced
Light dependent
GRANA
WATER
OXYGEN
ATP
Light independent
STROMA
CARBON DIOXIDE
C6H12O6