Can plants think?
Do plants have a
social life?
Pre-syringa leaf c.s.
Plants: Leaf Cross Section
Plants review:
 Vascular Tissue:


Xylem, transports water
Phloem, transports food
 Gas intake:

Guard cells open forming STOMATES
Stomates and Guard cells
PHOTOSYNTHESIS:
The starting point of life*
Experiment design
Experiment design: Is light necessary for photosynthesis?
Experiment….predict outcome
BLUE, EMPTY, LIGHT
EMPTY, LIGHT
LIGHT
DARK
RESULTS: explain
LIGHT
LIGHT
LIGHT
DARK
st
1
concept to know:
Living things run on
batteries.
What is the battery?
We recharge ATP
from sugar (glucose)
…where does sugar
come from?
Adenosine Triphosphate (ATP)
Molecule that provides life’s energy.
– Works by popping of a phosphate group,
releasing stored energy
– 3 parts:
Adenine
Ribose
3 Phosphate groups
Figure 8-3 Comparison of ADP and
ATP to a Battery
Section 8-1
ADP
ATP
Energy
Adenosine diphosphate (ADP) + Phosphate
Partially
charged
battery
Energy
Adenosine triphosphate (ATP)
Fully
charged
battery
An organism can either make
its own food, or eat it. They
are called
autotrophs or heterotrophs
Nutrition
Nutrition
Autotrophic
Nutrition
Photosy nthesis
Green Plants
Chemosy nthesis
Heterotrophic
Nutrition
Ingestion,
Digestion,
Egestion
PHOTOSYNTHESIS:
process which light
energy is converted into
sugar energy
PBS interactive
How do we know what goes in
and out of plants?
Major Players in the Development
of the Photosynthesis Equation
…how did they each contribute?
What where their results?
Conclusions?
• Van Helmont: what ingredient makes up
plants?
• Priestly: What are plant byproducts?
• Ingenhousz: Is light really that important?
• What was his conclusion?
• Of what was he ignorant?
Priestly
conclusion?
Ingenhousz
conclusion?
Conclusion of scientists:
formula
WHY ARE PLANTS GREEN?
The chloroplast: the plant 1º worker
Chloroplast Anatomy
The mechanics of
photosynthesis
Figure 8-7 Photosynthesis: An Overview
Section 8-3
water
CO2
Chloroplast
Chloroplast
NADP+
ADP + P
LightDependent
Reactions
Calvin
Cycle
ATP
NADPH
O2
Sugars
Photosynthesis
+
H2 O
CO2
Energy
Which splits
water
ATP and
NADPH2
Light is Adsorbed
By
Chlorophyll
ADP
NADP
Chloroplast
O2
Light Reaction
Calvin Cycle
Used Energy and is
recycled.
+
C6H12O6
Dark Reaction
Resources:
Light-Dependent Reactions
Photosynthesis animation,
VCAC
Photosynthesis video,
Mastering Biology
Photosystem II
Hydrogen
Ion Movement
Chloroplast
ATP synthase
Inner
Thylakoid
Space
Thylakoid
Membrane
Stroma
Electron
Transport Chain
Photosystem I
ATP Formation
Figure 8-11 Calvin Cycle
Section 8-3
CO2 Enters the Cycle
Energy Input
ChloropIast
5-Carbon
Molecules
Regenerated
6-Carbon Sugar
Produced
Sugars and other compounds
Comparison of
Mitochondria and
Chloroplasts
Both have a large amount of internal membrane
surface area.
Both have their own ribosomes.
Both have their own genomes.
Both produce a large amount of ATP.
Both derive energy for ATP synthesis from H+
pumps.
The mitochondrial genome (in
humans) is about 16,000
nucleotides long.
The chloroplast genome is about
10x the size of the mitochondrial
genome.
Quick Quiz
1. What is the ultimate purpose of photosynthesis?
2. Where does the Calvin Cycle occur?
3. What is the purpose of water?
4. What is the purpose of light?
5. What is the primary raw ingredient of sugar?
6. Where do the Light-Dependent Reactions occur?
7. What makes the turbine spin that makes ATP?
8. What is the waste product of the Light-Dependent Reactions?
9. Why are plants green?
Test yourself
Section 8-3
includes
use
to produce
takes place in
take place in
of
uses
to produce
Do Now
Section 8-3
Photosynthesis
includes
Lightdependent
reactions
use
energy from
sunlight
Calvin cycle
thylakoids
to produce
ATP
NADPH
takes place in
take place in
stroma
of
O2
Chloroplasts
ATP
uses
NADPH
to produce
High-energy
sugars
Chromatography Lab follow-up
Figure 8-5 Chlorophyll Light Absorption
Section 8-2
Absorption of Light by
Chlorophyll a and Chlorophyll b
Chlorophyll b
Chlorophyll a
V
B
G
YO
R
ENERGY ABSORPTION ON AN ATOMIC LEVEL
Chlorophyll, a green pigment molecule, allows plants to absorb light energy. A
pigment molecule obtains energy only at certain frequencies of light.
Energy insufficient to reach an excited state is not absorbed (click 1). Similarly,
energy that drives an electron past one energy level but is insufficient to reach a
second is not absorbed (click 1). To be absorbed, the energy must be sufficient to
reach only allowable energy states (click 1). This simple rule of quantum physics is
all you need to know to understand an absorption spectra of chlorophyll (click 1).
2
Chlorophyll b
Absorption
Intensity
excited states
1
ground state
Chlorophyll a
300
400
500
600
700
http://seawifs.gsfc.nasa.gov/SEAWIFS.html