11/13 turn in atp lab go over atp hw photosynthesis notes photo. vocab (due by end of class) quick...
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11/13
• Turn in ATP lab
• Go over ATP HW
• Photosynthesis Notes
• Photo. Vocab (due by end of class)
• Quick review (What's not done is HW)
Bio NOTES: PhotosynthesisWe know from previous lessons that all living things needenergy in order to survive, and that food provides the sourceof energy. But…where does the food come from?
Food is made by producers, such as plants and algae.
Photosynthesis = process where plants use energy from the sun to make their own food
Plants are also known as autotrophs because they maketheir own food by the process of photosynthesis.
Producers capture energy from sunlight to make their own source of chemical energy!
Chemical Equation
http://www.youtube.com/watch?v=mpPwmvtDjWw
In plants, chlorophyll is found inorganelles called chloroplasts.
Plants contain pigments that absorb sunlight and trap energy.The most common pigment is chlorophyll, which givesplants their green color.
Plants also contain red and orangepigments such as carotene thatabsorb light in other regions of thespectrum.
The spectrum of visible light
Energy from the sun travels to Earth in the form oflight. Sunlight is a mixture of differentwavelengths of light – many of these are visibleto your eyes.
• Plants absorb red and blue light from the sun to make food during photosynthesis
• Plants don’t need green light to make food, so it is reflected – which is why plants are green!
So…the best wavelengths of light for plant growth are red and blue while the worst wavelength of light for plant growth is green.
http://www.glencoe.com/sites/common_assets/science/virtual_labs/LS12/LS12.html
Inside the chloroplast
Photosynthesis occurs in chloroplasts.There are two major parts of a chloroplast: - grana (thylakoids) - stroma
● grana (thylakoids) - saclike membranes arranged in stacks - contains pigments - first part of photosynthesis occurs here
● stroma - region outside the thylakoid membranes - second part of photosynthesis occurs here
Light-Dependent ReactionsThe light-dependent reactions capture energy from sunlight. - takes place in thylakoids - water and sunlight are needed. -Water is absorbed through the roots - chlorophyll absorbs light energy - energy (ATP) is transferred along thylakoid membrane then to light-independent reactions - oxygen is released
Light-Independent Reactions
The light-independent reactions make sugar. - takes place in the stroma - needs carbon dioxide from atmosphere - uses energy (ATP) from light-dependent reaction to build a sugar in a cycle of chemical reactions
* Also called the Calvin cycle
C6H12O6
granum (stack of thylakoids)
thylakoid
sunlight
1 six-carbon sugar
6H2O
6CO2
6O2
chloroplastchloroplast1
2
43
energy
stroma (fluid outside the thylakoids)
6CO2 + 6H2O + sunlight C6H12O6 + 6O2
The equation for the overall process is:
Factors affecting Photosynthesis
● Water - shortage can slow or even stop photosynthesis - plants living in dry areas have a waxy coating to prevent water loss
● Temperature - enzymes used in photosynthesis function best between 0°C and 35°C - high or low temps slow down or stop photosynthesis
● Intensity of light - increasing light intensity increases the rate of photosynthesis - plants eventually reach their maximum rate of photosynthesis
Summary of Photosynthesis
Light Reactions
• Inputs:
Light
Water• Outputs:
ATP
Oxygen (O2)
OCCURS IN THYLOKOID
Dark reactions (Calvin cycle)
• Inputs:
◦ ATP
◦ CO2• Outputs:
◦ Glucose
OCCURS IN THE STROMA
Summary• Light reactions Calvin Cycle
Thylakoid StromaStroma
Glucose
Let’s review…
Light-d
ep
end
ent
reactio
ns
Lig
ht-
ind
ep
end
ent
react
ions
What materials come into the chloroplast that are used in the
light-dependent reactions?
What material comes into the chloroplast that is used by the
Calvin Cycle?
What material moves out of the chloroplast from the light-
dependent reactions?
What materials move out of the chloroplast from the Calvin Cycle?
What materials move from the light-dependent reactions to the Calvin
Cycle?
What materials move from the Calvin Cycle back to the light-
dependent reactions?
11/13
• Turn in ATP lab
• Go over ATP HW
• Photosynthesis Notes
• Photo. Vocab (due by end of class)
• Quick review (What's not done is HW)
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