cell energy why do cells need energy? how can cells store energy? a molecule called adenosine...
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Cell Energy
Why do cells need energy?
How can cells store energy? A molecule called adenosine
triphosphate ATP
Energy is stored in ________________Chemical Bonds
Cell Energy
Why does ATP have so much stored energy?
ATP can be recycled.
Why worry about Photosynthesis?
Food chains begin with the SUN! Autotrophs are the
first level of the food pyramid.
Heterotrophs eat autotrophs
Carbon sinks
atmosphere
What is Photosynthesis? Process used by autotrophs to
change the sun’s energy into chemical energy stored in organic molecules.
Trapping energy from sunlight and using it to build food (complex carbohydrates)
Plants, protists (algae), bacteria
Pigments and Wavelength of Light
Equation for Photosynthesis
6 CO2 + 6 H2O + sunlight
Glucose + 6 O2
The Chloroplast- Where Photosynthesis
HappensThe insides of leaf cells can contain a half million
chloroplasts per square mm of leaf surface
STROMASTROMA
GRANAGRANA THYLAKOIDTHYLAKOID
PIGMENTSPIGMENTS
Photosynthesis has:
•“Light Reactions”
•take place in the GRANA where electrons (e-) are excited by the sun’s energy and through the splitting of H2O
•“Dark Reactions”
•take place in the STROMA and are where the glucose is made.
The Light Reactionslight energy converted to chemical energy
(ATP and NADPH)Location: Thylakoid membranes of grana inside chloroplastReactants- Sunlight + waterProducts- ATP, O2 , H
NO SUGAR IS PRODUCED
The
The Light Reactions
GRANA
CHLOROPLAST
The Light Reactions: Photolysis Sunlight excites an electron and water
is split. O2 is released into atmosphere
ATP is made as electron falls down the Electron Transport Chain
Excited electron produces NADPH.
Both ATP and NADPH will take go to the DARK SIDE.
The Light Reactions
Welcome…to the DARK side
Calvin Cycle
Calvin Cycle• Produces complex carbs ( glucose, startch, cellulose)•Happens in stroma•Reactants:
•CO2 (from atmosphere)
•ATP (from light reactions)• Hydrogen (from NADPH)
•Product: Glucose! Sugar! FOOD!
Dark Reactions(Inside chloroplast not in grana)
CO2 enters the cell from the air.
CO2 combines with Hydrogen from the light reactions to form carbohydrates (like sugar and starch)
The Calvin Cycle
Photosynthesis EssayHave you ever heard that the chloroplasts
produce glucose? This is how they work. It starts with sunlight hitting the chloroplast. The energy of the sunlight is captured by chlorophyll. This energy is used to split water into hydrogen and oxygen. The oxygen is released. This process is called the light reaction.
The hydrogen is used in the dark reactions. Carbon dioxide combines with the hydrogen through a series of reactions called the Calvin Cycle which makes glucose. This process is photosynthesis.
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