Photosynthesis Flashcards
What is the granum
The stack of thylakoids
What is a thylakoid
A single part of the granum stack
What is the stroma
Inner area filled with enzymes
Why do chloroplasts have multiple pigments?
There’s different wavelengths so more pigment means more wavelengths are absorbed
What is a photo system
A group of pigments that work together to absorb as much wavelength as possible. They’re embedded into the thylakoid membrane
Describe the light dependent reaction
Light hits photo system
Chlorophyll molecule gets excited
Electrons leave molecule and move along electron transport chain
Energy lost and used to transport protons from stroma into thylakoid membrane space
NADP is final electron acceptor and becomes reduced
Protons activate ATP synthase
ADP + PI -> ATP
What is photolysis
H2O split into electrons and protons
Why does photolysis occur in the light dependent reaction
Replaces electrons lost when electrons leave photosystem
So reduces photosystem
What is photophosphorylation
Phosphorylation in the presence of light
Where is ATP made during the light dependent reaction
In the stroma
What adaptations do leaves have
Large SA collect as much light as possible
Stomata open and close as light intensity changes
Packed mesophyll so sunlight hits chloroplasts
Thin so short diffusion pathway
What is the word equation for photosynthesis
Co2 + water -> glucose + oxygen
What is the photosynthesis equation (not words)
6 Co2 + 6 H2O
->
C6H12O6 + 6 o2
What part of the light dependent reaction is cyclic photophosphorylation and how
Photosystem I
Electrons rejoin ETC allowing more energy to make ATP
What are the products of the light dependent reaction
ATP and NADPH
What is the light independent reaction also known as
The Calvin cycle
How many RUBP are produced for every 1 molecule of glucose made
6
What products are required for the Calvin cycle
ATP and NADPH
Why is the stroma the best place for the light independent reaction to take place
It has all the enzymes required for the cycle
Where does the light independent reaction take place
In the stroma
Describe the Calvin cycle
Co2 comes in RUBP joins co2 because of enzyme rubisco 6 carbon compound unstable so breaks into 2 3 carbon compounds = GP GP reduced by ATP and NADPH 2 TP molecules form Cycle happens 6 times then Carbon comes away to make glucose Spare TP used to regenerate RUBP
What is glucose from the light independent reaction used for
Make starch, lipids, cellulose, amino acids etc. Basically all organic molecules plant needs
In evidence experiment for Calvin cycle, why is co2 supplied to algae radioactively labelled
Allows the substances to be identified as CO2 in all of them
In evidence experiment of Calvin cycle, how might the hot methanol stop further chemical reactions taking place?
The high temperature and methanol denature the enzyme that catalyse reactions
