Lecture 11: Photosynthesis - 10/25 Flashcards
Redox reactions
Chemical reactions in which one element is reduced and another is oxidized; electrons are transferred from one component to another
What are the two phases in photosynthesis?
Light reactions and light-independent/”carbon linked” reactions
Chloroplasts
Organelles that synthesize chemical energy from light energy
Thylakoids
Stacks of discs inside chloroplasts
Lumen
The area inside thylakoids
Light reactions
Use light energy (endergonic, requiring energy) to produce ATP and NADPH
Stroma
The colorless fluid surrounding the thylakoids inside a chloroplast
Light-independent/”carbon-linked” reactions
Use chemical energy (ATP, NADPH) to drive the synthesis of CO2 into carbohydrates
Light harvesting complexes
Make up the photosystems and contain light energy-gathering pigments
What are the pigments that photosynthesize?
Chlorophyll and carotenoids
Why is having multiple types of pigments useful?
To absorb a wider spectrum of light
What are photosystems made of?
They are a chlorophyll-protein complex, composed of many proteins across the thylakoid membrane and many pigments
Reaction center
One special chlorophyll in the photosystem
This chlorophyll passes an electron to the next electron acceptor in the photosynthetic electron transport chain
Where does Photosystem II source its electrons from?
It gets its electrons from the photolysis of water, producing O2, H+, and e- (the electron)
How does an electron make its way through the photosystems?
First, it is separated from water through photolysis by Photosystem II. It then makes its way across the electron transport chain to Photosystem I where it is used to reduce NADP+ to NADPH
