Download Photosynthesis & Respiration Notes

I.
Pathway of Energy
A. Energy Flow Chart
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II. Photosynthesis – sunlight is captured
using chlorophyll and is converted into
chemical energy stored in bonds of
carbohydrates.
A. Information
1. Equation:
6CO2 + 6H2O chlorophyll + sunlight> C6H12O6 + 6O2
Carbon water
glucose oxygen
dioxide
REACTANTS
PRODUCTS
a) Chlorophyll is a green pigment found
in the chloroplast.
2. Autotroph – organism that uses
sunlight to make their own food.
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B. Where does it occur?
1. Occurs in the chloroplast
a)Chloroplasts consists of stacks of
membrane sacs called thylakoids.
1)Stacks of thylakoids are called
grana.
2)A fluid substance surrounds the
grana is called stroma.
3)Chlorophyll is in the thylakoid
membrane.
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Figure 8-6
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C. Two main Steps
1. Light Dependent Reactions:
a)Set of reactions that convert light
energy to chemical energy.
b)Occurs in the grana of thylakoid.
c)2 stages:
Stage 1:
 Sunlight is converted to electrical
energy -> electron transport.
 Sunlight is captured by chlorophyll
causing water molecules to split.
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Light Dependent Reaction Stage 1
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Stage 2:
 Electrons pass through the thylakoid
membrane through a process called electron
transport chain.
 ATP (energy) is formed by this process.
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2. Light Independent Reactions:
a)Set of reactions that produce organic
compounds, using the chemical energy
produced during the light dependent
reactions.
b)Occurs in the stroma (outside the
thylakoids).
c)Sometimes called ‘Dark Reactions.’
d)Uses the Calvin Cycle.
Calvin Cycle:
 Series of reactions where Carbon from CO2
is ‘fixed’ to form a 6-carbon molecule
(carbon fixation)  makes glucose.
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 C3 plant – plants that uses the Calvin
Cycle where two 3-carbon molecules are
joined together to form a 6-carbon
(glucose).
 CAM – Crassulacean Acid Metabolism; desert
plants take in CO2 at night and store as
acid till sunlight was present.
Advantage – prevents water moisture loss.
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III. Respiration – process by which living
organisms obtain energy from the bonds of
food molecules.
A. Information
1. Equation:
C6H12O6 + 6O2
 6CO2
+ 6H2O + ATP
glucose
oxygen
Carbon water energy
dioxide
2. Autotrophs + heterotrophs (cannot make
their own food).
3. Glucose (food) comes from
photosynthesis.
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B. 2 Types of Respiration:
1. Aerobic Respiration – respiration where
oxygen is abundantly present.
a)Produces large amounts of Adenosine
triphospate (ATP).
2. Anaerobic Respiration – respiration
where oxygen is NOT abundantly present.
a)Produces small amounts of ATP.
b)Also called fermentation.
C. The Cellular Respiration Process
1. Glucose enters the body as food 
digested  taken into the cells by the
bloodstream.
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2. Glycolysis – process by which glucose
(6-carbon sugar) is broken down into
2 pyruvic acid molecules (3-carbon)
a)Occurs in the cytoplasm of the cell.
b)Produces 2 ATP from the breaking of
the bonds in glucose.
c)Figure 9-2, page 222
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3.Krebs Cycle:
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 Summary:
Process
Glycolysis
Krebs Cycle
E- Trans. chain
TOTAL
Aerobic
2 ATP
2 ATP
32 ATP
36 ATP
Anaerobic
2 ATP
0 ATP
0 ATP
2 ATP
 Aerobic respiration is more efficient,
because it produces more energy.
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D. Adenosine triphosphate, ATP
1. Composed of Adenine, ribose, 3
phosphate groups.
2. Figure 8-2, p. 202
1. ADP vs. ATP
a)ADP = adenosine diphosphate (2)
b)ATP = adenosine triphosphate (3)
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E. Anaerobic Respiration
1. Lactic Acid Fermentation:
a)Occurs in animal cells (muscle
cells).
2. Alcoholic Fermentation:
a)Occurs in plant cells and yeast.
b)Beer + wine is made this way.
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F. Photosynthesis vs. Cell Respiration
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IV. Oxygen, Carbon, and Nitrogen Cycles
A. Oxygen + Carbon Cycles
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B. Nitrogen cycle
1. N makes up to 78% of the atmosphere.
2. Nitrogen fixation – N2 gas is ocnverted
to ammonium compounds (NH4OH).
3. Ammonification – bacteria breakdown
waste and decaying organisms to form
ammonium compounds (NH4OH).
4. Nitrification – bacteria form nitrites
(NO2) and nitrates (NO3).
5. Denitrification – bacteria breakdown
nitrites and nitrates to form N2 gas.
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