Photosynthesis Flashcards
How is light E stored?
Converted into chemical energy and stored in the form of a 3C and then converted to a 6C
Photosynthesis equation
6CO2 + 6H2O –> C6H12O6 + 6O2
Stage 1 of photosynthesis
Basically, happens in the membrane system and in the thylakoid of cells called the light reactions.
Takes in light and uses E to convert ADP and NADP+ to ATP and NADPH (e- carrying molecule)
Stage 2 of photosynthesis
Called the calvin cycle
*ATP and NADPH produced, their energy is used to Fix carbon i.e turn Carbon and H2O into sugar
Where do light reactions occur?
Thylakoid space
Why is the thylakoid space important?
*Increased SA for maximisation of capturing light
*Proton gradient built inside the thylakoid space
Where does Carbon fixation occur?
In the stroma
Where does light reaction occur?
On the thylakoid membrane
How is light captured?
The particle of light is absorbed by pigments aka chlorophyll found in protein complexes called photosystems, embedded in the thylakoid membrane.
Light E absorbed by chlorophyll releases a high E e- that travels through the photosynthetic electron transport chain
Photosynthetic e- transport chain
2 protein complexes
Goes through PII, High energy e-s collected and transported to another protein complex that doesn’t absorb light Cytochrome
This protein complex uses some E from the e- to pump H+s across the membrane
Goes to photo II where more light is absorbed and it gets a booster yay
Endpoint is the NADPH
What is done to reciver the 2 e-s lost in the process?
H2O broken down in thylakoid space to buildup –> 1/2O2 + 2H+ (more proton gradient yay
What happens in Carbon fixation/Calvin cycle
3CO2 –> 3 carbon sugar which is used to make glucose and other molecules
3 stages of C fixation
- Fixation
- Reduction
Fixation of CO2
5C molecule + CO2 –> 2x 3C molecules that have low energy
*No energy is used in this process and enzyme protein catalyses this reaction
Reduction
Taking the low E 3C –> high E 3C using the ATP –> ADP and the high E e-s from the 6NADPH –> 6NADP+
