Photosynthesis
Entropy
Lots of energy in a system to less energy in a system
1. thermodynamic quantity representing the unavailability of a system's
thermal energy for conversion into mechanical work, often interpreted as the
degree of disorder or randomness in the system.
2.2.
lack of order or predictability; gradual decline into disorder.
Study guide question 19, 20, 21, 40, 43,
Going from order (lots of energy) to disorder in a system. Your room
will get dirty unless you decrease the entropy by adding cleaning
energy into your system.
Our body, and a plants do not
have entropy because we
continually put energy (food
or sunlight) into our system.
If we didn’t eat or drink, our
bodies would have entropy.
Energy is needed to maintain
Homeostasis.
 Examples
Muscle Cell Contraction
Moving ions by active transport
Break down & build up molecules
Metabolism !
Brain functions
To keep warm (75% or more !)
Moving
Carbohydrates & fats for Stored
Energy
This is Potential Energy
Plants capture sunlight
Store Chemical energy in the form of ATP
Troph= Feed
Autotrophs = Self Feed
Organisms
can use
Sunlight
directly to
make food
(chemical
energy) from
inorganic
molecules
 The Energy currency in the cell to transfer
energy from sun or chemical bonds (food)
to whatever our cells need to do is stored in
the compound ATP
 Adenosine Triphosphate
 Adenine + Ribose + 3 Phosphates
3 phosphates
ATP Has
3 Phosphates
stores energy
Study guide 44, 45, 46,
2 phosphates
ADP has 2 phosphates and is
used energy
Sodium-Potassium Pump
 This
exchange
allows
muscles to
contract
and relax.
Van Helmont Thought Dirt caused
Plants to Grow
Year 1 Dirt =5Kg,
plant = 3kg
Year 5 Dirt =5Kg,
Plant =25kg
Result: Dirt Does NOT give the
plants energy (food) to grow
Pastor Priestly found that plants made a
candle burn longer than a candle without it
in a jar.
He repeated this experiment with a mouse
and a plant.
Ingenhausz Light and Dark
From those experiments, the
photosynthesis equation was
created
Study Guide question 11, 59, 62, 67
 Carried out by autotrophs.
 Equation
6CO2 + 6H2O + light
C6H12O6 + 6 O2
 Reactants are the ingredients
 Products are the molecules that are
made
Study Guide question 3,22, 24, 28, 52
Stroma is liquid
Light reaction occurs in the
Membranes called Grana.
These are stacked molecules
of Thylakoids
Light Spectrum
 Light is a form of Radiation.
 Radiation has different
wave lengths based upon
their energy levels.
 Sunlight is Visible (white)
light
 Contains ALL colors:
ROYGBIV
 Least to most energetic
We see what is Reflected, NOT
Absorbed !
How plants absorb light
 Plant Pigments absorb useful wavelengths
 The color you see is reflected light
 Chlorophyll is the primary pigment and is the color
green.
 So it reflects green and absorbs red, yellow, blue, violet
Two Types
 Chlorophyll A: Mostly RED & Violet
 Chlorophyll B: Blues & Orange
 Carotenoids are the second major pigments
 Absorbs light blue to deep green
 Reflect Orange (Red and Yellow)
Chlorophyll Pigment in
Chloroplast.
Study Guide question 37
Study Guide question 2, 33, 70
Chlorophyll a and b
If it gets too hot, the
stomata will close and
not take in any CO2
Photosynthesis Formula involves two
steps. First step is to get the ingredients
and the second step is to make the
sugar.
6CO2 + 6H2O+ Light Energy
C6H12O6 + 6O2
Light Dependent Part
Light Independent Part
Study Guide question 53, 72
Photosynthetic Process
Light Reactions – requires
sunlight to capture & make
energy
Calvin Cycle - Dark
Independent of sunlight.
Can occur day or night – at anytime
Uses energy to make glucose (sugar)
Study Guide question 14, 15, 16
Light Dependent
Light Dependent Reaction
Light + H2O
+
H
+ ATP + O2
1. Light energy absorbed
2. NADP+  NADPH
3. O2 Production
(thank a plant as you breath !!)
Sunlight splits 2 H2O molecules 
O2 + 4H+ + 4e4. ATP formation
 Energy built up due to charge difference
across membrane
 P + ADP + energy  ATP
Calvin Cycle
 Takes place in the stroma
of the chloroplast.
 Goal: To synthesize organic
molecules (as sugar) from
inorganic CO2.
 CO2 comes in through the
pores of the leaves called
stomata.
 H+ comes from the light
reaction
 ATP from light reaction
provides the energy.
 This is an energy conversion
from ATP to Glucose.
H+ + ATP + CO2
C6H12O6
Calvin Cycle Making a
Sugar
Study Guide question 49
Light Independent
Study Guide question 41, 63,
Calvin Cycle
Notice that to
create one
sugar, it
requires
9 ATPs
Creation of a Sugar Molecule
Gas
Exchange
in a Plant
 This conversion of CO2 into C6H12O6 is
crucial to life on Earth. This is one of the
only reactions that is able to trap C into an
organic molecule.
 The main products are Carbohydrates
 Sugars (Glucose, Sucrose), Starch or
Cellulose
 These can be converted by the cell into
most molecules needed by the plant.
 This molecule is the basic building block
needed for the plant growth and energy
In each liquid is BTB, which will turn yellow in
the presence of CO2
What Color will D, C, A liquid be?
What would happen if the mouse were running on a wheel?
Study Guide question 4, 5, 6
Things That Affect Rates of
Photosynthesis
Amount of Light
Study Guide question 10,11, 12, 13
Things That Affect Rates of
Photosynthesis
Intensity of Light
Study Guide question
12,74, 75
Light Intensity
Temperature
Things That Affect Rates of
Photosynthesis
Study Guide question 32
Temperature
# of Produced Bubbles
Study Guide question
12,74, 75
# of Produced Bubbles
Things That Affect Rates of
Photosynthesis
Decrease in Temperature
30 20
15
10
5
0
# of Produced Bubbles
Things That Affect Rates of
Study Guide
Photosynthesis
question
12,74, 75
Amount of Water
More Water
Which is has more entropy
(disorder) Ice or water?