Photosynthesis Why plants don’t “eat”
What is Photosynthesis? Photo: Light Synthesis: Putting Together Photosynthesis: putting together with light!
Why are plants green? Chlorophyll absorb light All but green Green is reflected back!
What are the two stages? 1st: Light-Dependent Reactions 2nd: Light-Independent Reactions
Where do Light-Dependent Reactions Occur? In the thylakoid stacks of the chloroplast
What happens during the light-dependent reactions? Sunlight powers the production of ATP Water is broken down into oxygen What is a waste product here?
What are the steps of Light-Dependent Reactions? Photosystem II Photosystem I ATP Synthase
What happens during Photosystem II? Chlorophyll absorbs sunlight Sunlight powers electrons to leave H from H20 and move through membrane H+ moves through membrane If H leaves water, what is left?
What happens during Photosystem I? Chlorophyll still absorbs sunlight Electrons (e-) added to NADP+ to make NADPH NADPH moves to the ATP Synthase NADP+ ATP Synthase Photosystem I NADPH
What happens during ATP Synthase? H+ ions move back through membrane Power ATP Synthase to make ADP from ATP Where have we seen this before?
Where do Light-Independent Reactions Occur? In the stroma of the chloroplast
What happens during Light-Independent Reactions? ATP made previously powers making of Glucose CO2 is used to make C6H12O6 (Glucose)
How many steps are there in Light-Independent Reactions? ONE! The Calvin Cycle
What happens during the Calvin Cycle? 1. A 5-Carbon molecule attaches to a C from CO2 to become a 6-Carbon molecule
2. Energy (ATP) breaks the 6-carbon into 2 3-carbon molecules
3. 1 of the 3-carbon molecules leaves the cycle, the other continues on.
4. Remaining 3-carbon has energy (ATP) added to become the 5-carbon molecule we started out with!
So how does that make a Glucose? Glucose has 6 carbons… The 3-carbon molecule that left, after 2 cycles, comes together to make Glucose! 3C+3C=6C