Photosynthesis 3.5.1 Flashcards
Where does the Light Dependent Reaction occur?
Thylakoids membranes (granum or grana)
Why are multiple pigments present in thylakoids?
This is to absorb as many different wavelengths of light to use in the LDR; resulting in a greater rate of photosynthesis
What is a Photosystem and what is it role?
A group of pigments absorbing light energy with a central chlorophyll molecule
What happens when light is absorbed by photosystem 2?
Pair of electrons is excited and is raised to a higher energy level, chlorophyll is ionised and this is called ‘photoionisation’.
What is the purpose for photolysis and what happens?
This is to replace electrons lost at photosystem 2. Water is broken down into electrons & protons and a waste product of oxygen.
What are the products of the light dependent reaction?
NADPH & ATP
How is ATP produced in the light dependent reaction?
Photophosphorylation
How is reduced NADP formed?
The hydrogen atoms formed from the protons and electrons combining will reduce NADP in the stroma.
What are the products of the light dependent reaction used for?
Light Independent reaction
What is the function of reduced NADP in the light independent reaction?
It supplies the reducing power as the reaction is a reduction reaction
Where does the Light Independent Reaction occur?
Stroma (Solution in chloroplast)
What is the structure of Ribulose Bisphosphate?
It has 5 carbons and 2 phosphate groups
What is the function of Ribulose Bisphosphate?
Acts as a CO2 Acceptor, thus, combines with a molecule of CO2 to produce an unstable 6 carbon compound via ‘Carbon Dioxide Fixation’.
What enzyme is involved in the Light Independent Reaction?
Ribulose Biphosphate Carboxylase a.k.a Rubisco
How is Glycerate 3 phosphate formed?
This is via the breakdown of the unstable 6 carbon intermediate forming 2 molecules of glycerate 3 phosphate with enzyme Rubisco.
