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I. Pathway of EnergyA. 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. Information1. Equation:6CO2 + 6H2O chlorophyll + sunlight> C6H12O6 + 6O2

Carbon water glucoseoxygen

dioxideREACTANTS PRODUCTSa) 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 Steps1. 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. Information1. Equation:

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

glucose oxygen Carbon water energy

dioxide2. 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 Process1. 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 Aerobic Anaerobic

Glycolysis 2 ATP 2 ATPKrebs Cycle 2 ATP 0 ATPE- Trans. chain 32 ATP 0 ATPTOTAL 36 ATP 2 ATP

Aerobic respiration is more efficient, because it produces more energy.

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D. Adenosine triphosphate, ATP1. Composed of Adenine, ribose, 3

phosphate groups.2. Figure 8-2, p. 202

1. ADP vs. ATPa)ADP = adenosine diphosphate (2)b)ATP = adenosine triphosphate (3)

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E. Anaerobic Respiration1. 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 CyclesA. Oxygen + Carbon Cycles

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B. Nitrogen cycle1. 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.