5.2.4 - Light dependent reactions Flashcards
Where do light dependent reactions occur?
Thylakoid membranes
Where are photosystem 1 and 2 found?
1 = Integranal lamallae
2 = Granal lamallae
What is the process in which water is broken down and what is it broken down into?
Photolysis
Oxygen, protons and electrons
What are the products of non-cyclic photophosphorylation?
NADPH and ATP
What do light photons do at photosytem 1 and 2?
They excite electrons causing them to move between electron carriers
What does the energy formed from the movement of electrons between carriers cause?
Hydrogen ions to be actively transported from stroma to thylakoid lumen
What happens as the concentration of hydrogen ions in the thylakoid lumen builds up?
They pass through ATP synthase by chemiosmosis which synthesises ATP
What happens to NADP in non-cyclic photophosphorylation?
It is reduced by electrons to form NADPH
Where in non-cyclic photophosphorylation does photolysis occur?
At a water splitting complex attached to photosystem 2.
What happens when photosystems 1 and 2 lose electrons in the z-scheme?
Electrons Lost by PS2 are replaced by electrons from the splitting of water.
Electrons lost by PS1 are replaced by the excited electrons from PS2
State the differences between cyclic and non-cyclic photophosphorlyation.
Cyclic phosphorylation only involves photosystem 1
Also doesn’t produce NADPH
What is the product of cyclic photophosphorylation?
ATP
Does photolysis occur in cylic photophosphorylation?
NO
