chloroplast - lecture 12 Flashcards
What are the main structures of chloroplasts?
- stroma
- Thylakoid
- Granum
- Intermembrane space
- inner and outer membranes
Why is light needed in the chloroplast ETC?
The electrons that get passed along the ETC in chloroplasts come from water. Water is a poor donor of electrons and a lot of energy is required to extract the electrons from water. The energy source to do this is light
How is sunlight utilised in chloroplast molecules?
-Sunlight is absorbed by chlorophyll molecules and electrons interact with photons of light raising them to a higher energy level
What are photosystems and what are they made up of?
- consist of an antenna complex and a reaction centre
What does the antenna complex do?
collects the energy from sunlight and channels energy to a pair of electrons in the reaction centre
What are the 3 mobile electron carriers?
- plastoquinone
- Plastocyanin
- Ferredoxin
What is plastoquinone like?
closely resembles ubiquinone of mitochondria)
Description of plastocyanin
a small copper containing protein
What is Ferredoxin?
a small protein contains an iron - sulphur centre
How is H plus generated in photosynthesis?
The splitting of water
What are the high energy electrons passed onto in the end?
NADPH
What is ATP and NADPH used for?
- carbon fixation
- for every 3 carbon sugar produced 9 molecules of ATP and 6 NADPHs are required
What does Rubisco do?
catalyses the initial reaction in carbon fixation .
Very slow enzyme .
What is Ribulose bisphosphate (RuBP)?
a 5 carbon molecule in which a carbon is added to
What happens in the thylakoid / thylakoid membrane?
Photosystems I and II,
ATP synthase, NADP reductase
