2007-08
Unit 2: Cells
Chapter 8-2 & 3

• 1. Describe ATP including how energy is released and how it is recharged.
• 2. Explain the photosynthesis equation including the reactants and products.
• 3. Explain how chlorophyll works.
• 4. Describe both reactions for photosynthesis including location, reactants and products.
2007-08

• ATP (Adenosine triphosphate) :
– Chemical energy used by cell
– “ Battery ” of the cell: can be recycled
– “tri-phosphate” = 3 phosphates
Hi! I’m ATP!
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• How ATP gives up it’s energy:
– The 3 rd phosphate’s bond is broken and this supplies energy.
– The molecule is now ADP (adenosine diphosphate: 2 phosphates )
• To recharge the “battery”:
– Add a 3 rd phosphate group
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• Light energy from the sun, water , & carbon dioxide (CO
2 plants
) are absorbed by
• Plants make glucose ( C
6 release oxygen (O
2
)
H
12
O
6
), and
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6 CO
2
+ 6 H
2
O + light  C
6
H
12
O
6
+ 6 O
2
Carbon dioxide + water + light  glucose + oxygen
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• Chloroplast contains pigments:
– pigments trap light energy from the sun
– Chlorophyll absorbs blue & red but reflects green light
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2007-08

– Thylakoids : disk shaped structures where chlorophyll is found and where photosynthesis takes place.
• Grana : stacks of thylakoids
– Stroma : space outside the thylakoids where the Calvin cycle takes place
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• 2 reactions occur:
– Light-dependent reactions
• energy from sunlight & H
2
O is transferred to produce ATP and
NADPH
• O
2 is produced
• occurs in the thylakoids
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– Calvin Cycle (light independent reactions)
• CO
2
& energy in ATP and NADPH molecules are used to make glucose
• occurs in the stroma
2007-08

2007-08

• 1. Describe ATP including how energy is released and how it is recharged.
• 2. Explain the photosynthesis equation including the reactants and products.
• 3. Explain how chlorophyll works.
• 4. Describe both reactions for photosynthesis including location, reactants and products.
• 5. Draw the chloroplast and label its parts.
2007-08