Photosynthesis
here comes the sun
https://www.youtube.com/watch?v=Y6GNEEi7x4c
Where do all living things ultimately get
energy?
https://www.youtube.com/watch?v=g66NL4o_Mq8
Pay attention to energy inputs:
https://www.youtube.com/watch?v=25BOohiCF5A(19:00 minutes)
Where do all living things ultimately get energy?
How? Through photosynthesis!
$$$!
$$$!
$$$!
Through photosynthesis!
But first, remember ATP!
• ADP + Pi+ ENERGY!
Adenosine P P P
Adenosine P P P+
How can a molecular bond have “high energy?”
• Molecules want to get to the most stable state -
How can a bond have “high energy?”
• Molecules want to get to the most stable state - the higher energy they have the less stable they are
Potential Energy
ATP-ADP Cycle!
Back to…photosynthesis!(Plants (usually) can’t
eat!)
Photosynthesis Equation
What other process does this remind you of?
Photosynthesis Equation
What other process does this remind you of?
CELLULAR RESPIRATION (flipped)!
Origins
1) What are the graph axes? 2) What process led to the peak in stage 5? 3) Which cell organelle caused the drop in
stage 5?
bacterial origins
All stages of photosynthesis take place in the chloroplast
Let’s watch Zach’s video!
Find the chloroplast in your plant cell:
Anatomy of a chloroplast
Remember, chloroplasts are in the cells of
leaves…
Photosynthesis Equation
Photosynthesis Inputs
Carbon Dioxide- CO2
Image: zirconicusso / FreeDigitalPhotos.net
C02 enters through stomata
Stomata
Water - H2O
Image: zirconicusso / FreeDigitalPhotos.net
water from the roots
Sunlight
Image: healingdream / FreeDigitalPhotos.net
Photosynthesis Outputs
ATP!
Adenosine P P P
Oxygen & Water
C3 Stem Molecules• These can be built into
carbohydrates, lipids, and proteins!
Glucose (or Fructose) (carbs)
Text
Image: arkorn / FreeDigitalPhotos.net
Cellulose (carbs)
Image: Chris Sharp / FreeDigitalPhotos.net
Lipids & Proteins
photosynthesis has two reaction steps
2
1reactions
take place only in the presence of light and produce ATP
light-dependent
2reactions
do not need light & create organic molecules
light-independent
Overview of both steps
ATP!
The Light Reaction• goal: to make loads of ATP
• Inputs:
Sunlight
Image: healingdream / FreeDigitalPhotos.net
Water
Image: zirconicusso / FreeDigitalPhotos.net
Light Reaction
• Outputs:
ATP!
Adenosine P P P
Oxygen!
O O
The Light Reaction
requires light!
ONLY red and blue light
the pigment chlorophyll is found on the thylakoid membranes
what makes leaves green?
the pigment chlorophyll is found on the thylakoid membranes
what about leaves in Fall?
The Light Rxn
• To the board
To summarize:
The plant uses sunlight to split water to produce a ton of ATP.
The Light Independent Reaction
a.k.a. the dark reaction
Light Indep. Rxn
• Goal: to produce C3 stem molecules
• Inputs:
Carbon Dioxide- CO2
Image: zirconicusso / FreeDigitalPhotos.net
CARBON FIXATION
ATP!
Adenosine P P P
Light Indep. Rxn
• Goal: to produce C3 stem molecules
• Outputs:
C3 Stem Molecules• These can be built into
carbohydrates, lipids, and proteins!
Water (from both)
happens in stroma
the stroma is a liquid substance around the thylakloids
• To the board
To summarize:
• CO2 was rearranged into C3 molecules
• ATP was used and H2O was made
Overview of both steps
ATP!
water
The overall reaction for photosynthesis
6 CO2 + 12 H2O + light → C6H12O6 + 6 H2O + 6 O2
Now for…
• Complicated, but contextual, MOVIE:
• https://www.youtube.com/watch?v=YeD9idmcX0w
Revision clarification• Go to teacher page, print revision
sheet, and follow instructions! Answer questions found on the sheet – you’re not revising your quizzes directly.
• The revisions will help you learn to use resources you have. They break down questions to help with problem solving. See me with any questions that remain.
• Due Friday 3:30 pm, Earth Lab.
GradingA+ - Above and beyond in every way!
A – greater than 92
A- -- greater than 89 – 92
B+ -- greater than 85 – 89
B – greater than 81 – 85
C+ -- greater than 77 – 81
C – greater than 73 – 77
C- -- greater than 69 to 73
D – 50 to 69 F – below 50
Photosynthesis Drawings Should Include…
1) The 2 stages of photosynthesis
2) The inputs and outputs of photosynthesis, and how they enter and exit the chloroplast
3) The role and location of each of the items on the photosynthesis vocabulary list
4) Colors to distinguish between cell parts in your drawing and the stages of photosynthesis
• Giant water lilies: https://www.youtube.com/watch?v=igkjcuw_n_U&list=PLCC07E66503F99BB5