Title: Photosynthesis Life Is Solar Powered!
1PhotosynthesisLife Is Solar Powered!
2What Would Plants Look Like On Alien Planets?
3Why Would They Look Different?
- Different Stars Give off Different types of light
or Electromagnetic Waves - The color of plants depends on the spectrum of
the stars light, which astronomers can easily
observe. (Our Sun is a type G star.)
4Anatomy of a Wave
- Wavelength
- Is the distance between the crests of waves
- Determines the type of electromagnetic energy
5Electromagnetic Spectrum
- Is the entire range of electromagnetic energy,
or radiation - The longer the wavelength the lower the energy
associated with the wave.
6Visible Light
- Light is a form of electromagnetic energy, which
travels in waves - When white light passes through a prism the
individual wavelengths are separated out.
7Visible Light Spectrum
- Light travels in waves
- Light is a form of radiant energy
- Radiant energy is made of tiny packets of energy
called photons - The red end of the spectrum has the lowest energy
(longer wavelength) while the blue end is the
highest energy (shorter wavelength). - The order of visible light is ROY-G-BIV
- This is the same order you will see in a rainbow
b/c water droplets in the air act as tiny prisms
8Light Options When It Strikes A Leaf
- Reflect a small amount of light is reflected
off of the leaf. Most leaves reflect the color
green, which means that it absorbs all of the
other colors or wavelengths. - Absorbed most of the light is absorbed by
plants providing the energy needed for the
production of Glucose (photosynthesis) - Transmitted some light passes through the leaf
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10Photosynthesis Overview
Concept Map
Photosynthesis
includes
Light independent reactions
Light dependent reactions
occurs in
uses
occur in
uses
Thylakoid membranes
Light Energy
Stroma
NADPH
ATP
to produce
to produce
of
ATP
NADPH
O2
Chloroplasts
Glucose
11Anatomy of a Leaf
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13Chloroplast
14Chloroplast
- Are located within the palisade layer of the leaf
- Stacks of membrane sacs called Thylakoids
- Contain pigments on the surface
- Pigments absorb certain wavelenghts of light
- A Stack of Thylakoids is called a Granum
15Pigments
- Are molecules that absorb light
- Chlorophyll, a green pigment, is the primary
absorber for photosynthesis - There are two types of cholorophyll
- Chlorophyll a
- Chlorophyll b
- Carotenoids, yellow orange pigments, are those
that produce fall colors. Lots of Vitamin A for
your eyes! - Chlorophyll is so abundant that the other
pigments are not visible so the plant is
greenThen why do leaves change color in the fall?
16Color Change
- In the fall when the temperature drops plants
stop making Chrlorophyll and the Carotenoids and
other pigments are left over (thats why leaves
change color in the fall).
17- The absorption spectra of three types of pigments
in chloroplasts
18- The action spectrum of a pigment
- Profiles the relative effectiveness of different
wavelengths of radiation in driving photosynthesis
19- The action spectrum for photosynthesis
- Was first demonstrated by Theodor W. Engelmann
20Chlorophyll
- Chlorophyll a
- Is the main photosynthetic pigment
- Chlorophyll b
- Is an accessory pigment
21PHOTOSYNTHESIS
- Comes from Greek Word photo meaning Light and
syntithenai meaning to put together - Photosynthesis puts together sugar molecules
using water, carbon dioxide, energy from light.
22Happens in two phases
- Light-Dependent Reaction
- Converts light energy into chemical energy
- Light-Independent Reaction
- Produces simple sugars (glucose)
- General Equation
- 6 CO2 6 H2O ? C6H12O6 6 O2
23First Phase
- Requires Light Light Dependent Reaction
- Suns energy energizes an electron in chlorophyll
molecule - Electron is passed to nearby protein molecules in
the thylakoid membrane of the chloroplast
24Excitation of Chlorophyll by Light
- When a pigment absorbs light
- It goes from a ground state to an excited state,
which is unstable
25- If an isolated solution of chlorophyll is
illuminated - It will fluoresce, giving off light and heat
26ETC
- Electron from Chlorophyll is passed from protein
to protein along an electron transport chain - Electrons lose energy (energy changes form)
- Finally bonded with electron carrier called NADP
to form NADPH or ATP - Energy is stored for later use
27Two Photosystems
- Photosystem II Clusters of pigments boost e- by
absorbing light w/ wavelength of 680 nm - Photosystem I Clusters boost e- by absorbing
light w/ wavelength of 760 nm. - Reaction Center Both PS have it. Energy is
passed to a special Chlorophyll a molecule which
boosts an e-
28- A mechanical analogy for the light reactions
29Photosystem
- A photosystem
- Is composed of a reaction center surrounded by a
number of light-harvesting complexes
30Where those electrons come from
- Water
- Electrons from the splitting of water
(photolysis) supply the chlorophyll molecules
with the electrons they need - The left over oxygen is given off as gas
31The Splitting of Water
- Chloroplasts split water into
- Hydrogen and oxygen, incorporating the electrons
of hydrogen into sugar molecules
32High Quality H2O
- Photolysis Splitting of water with light energy
- Hydrogen ions (H) from water are used to power
ATP formation with the electrons - Hydrogen ions (charged particle) actually move
from one side of the thylakoid membrane to the
other - Chemiosmosis Coupling the movement of Hydrogen
Ions to ATP production
33- Animation takes a min. to loadbe patient
- Animation II Does not take as long to load but
it is not as good
34- The light reactions and chemiosmosis the
organization of the thylakoid membrane
35Vocabulary Review
- Light-Dependent
- Pigment
- Chlorophyll
- Electron Transport Chain
- ATP
- NADPH
- Photolysis
- Chemiosmosis
36Light-Dependent
- Converts light into chemical energy (ATP NADPH
are the chemical products). Oxygen is a
by-product
37Pigment
- Molecules that absorb specific wavelengths of
light - Chlorophyll absorbs reds blues and reflects
green - Xanthophyll absorbs red, blues, greens reflects
yellow - Carotenoids reflect orange
38Chlorophyll
- Green pigment in plants
- Traps suns energy
- Sunlight energizes electron in chlorophyll
39Electron Transport Chain
- Series of Proteins embedded in a membrane that
transports electrons to an electron carrier
40ATP
- Adenosine Triphosphate
- Stores energy in high energy bonds between
phosphates
41NADPH
- Made from NADP electrons and hydrogen ions
- Made during light reaction
- Stores high energy electrons for use during
light-Independent reaction (Calvin Cycle)
42Chemiosmosis
- The combination of moving hydrogen ions across a
membrane to make ATP
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44PART II
- LIGHT INDEPENDENT REACTION
- Also called the Calvin Cycle
- No Light Required
- Takes place in the stroma of the chloroplast
- Takes carbon dioxide converts into sugar
- It is a cycle because it ends with a chemical
used in the first step
45Begins Ends
- The Calvin Cycle begins and ends with RuBP
- CO2 is added to RuBP fixing the CO2 in a
compound - One compound made along the way is PGAL
- PGAL can be made into sugars or RuBP
- Calvin Cycle uses ATP NADPH
46Phase 1 Carbon fixation
Phase 3Regeneration ofthe CO2 acceptor(RuBP)
Phase 2Reduction
47Chloroplast Where the Magic Happens!
H2O
CO2
Energy
ATP and NADPH2
Which splits water
Light is Adsorbed By Chlorophyll
Calvin Cycle
ADP NADP
Chloroplast
Used Energy and is recycled.
O2
C6H12O6
Light Reaction
Dark Reaction
6 CO2 12 H2O Light energy ? C6H12O6 6 O2
6 H2 O