PHOTOSYNTHESIS

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PHOTOSYNTHESIS
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The Need For Food (Review)

• Where does food come from?
• Autotroph
• Own Food
• Sun as energy to create food
• Heterotroph
• Others Food
• Eat other to obtain food and use energy

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The Need for Food (Review)

• How do use light to make food?
• PHOTOSYNTHESIS!
• 6 CO2 6H2O sunlight ? 6O2 C6H12O6 (Chemical
  energy)
• Makes glucose (basic food molecule for most
  living organisms)

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How do Plants Use Glucose?

• Immediately uses the energy stored in glucose to
  live (through cell respiration)
• Builds plant body from long chains of glucose
• Cellulose (structure) wood, bark, leaves
• Starch (stored energy) potatoes, roots

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What exactly is photosynthesis?

• The process of converting solar energy into
  chemical energy.
• Responsible for removal of 200 billion tons of
  C from the atmosphere yearly.

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What exactly is Photosynthesis

• Two step process
• Light dependent reactions
• Dark reactions (Calvin Cycle)
• Both take place inside the chloroplasts

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In the chloroplast
Takes Place inside chloroplast
Dark Reactions
CO2
ATP
NADPH
Light Reactions
Sugars
H2O
O2
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Light Dependent Reactions

• Chlorophyll in the chloroplasts absorb light
• Creates green color in plants because it DOES NOT
  absorb green light
• Roots absorb water

Chlorophyll b
Chlorophyll a
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Light Dependent Reaction

• Uses water and light and ADP to create O2 and
  ATP
• ATP is stockpiled during the day or light
  producing times.

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What is ATP?

• Chemical energy molecule used in
• Active Transport
• Energy to move organelles
• Protein synthesis
• Sugar molecule stores 90xs more energy then ATP
  does.

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ADP and ATP continued
Section 8-1
ADP
ATP
Energy
Energy
Adenosine diphosphate (ADP) Phosphate
Adenosine triphosphate (ATP)
Partially charged battery
Fully charged battery
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The Calvin (DARK) Cycle

• CO2 enter the plant through stomata (tiny holes
  in the leaf surface)

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The Calvin (Dark) Cycle

• CO2 combines with the energy from ATP (created in
  light cycle) to make glucose and ADP
• Where does the ADP and go?
• Back to the light dependent reactions

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H20
Light
Chloroplast
Chloroplast
NADP
ADP P
Light- Dependent Reactions
Calvin Cycle
ATP
NADPH
O2
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To sum up

• There are two parts to the photosynthesis
  equation
• Light dependent reactions
• Light Water ? O2 and Chemical energy
• Calvin Cycle
• Chemical energy and CO2 ? Glucose

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Factors that increase/decrease Photosynthesis Rate

• Water
• Temperature
• Light Intensity