photosynthesis what the fuck Flashcards
What is the chloroplast?
It is a eukaryotic organelle that absorbs energy from sunlight
What does the spilting of H20 do?
it provides the electrons for photosynthesis
What is the stroma? What occurs here?
it is a dense fluid within the chloroplast
the calvin cycle
What are thylakoids? What occurs here
they are sacs within the stroma, they contain plant pigments and are the sites of light reactions
What are granums?
they are thylakoids stacked in columns
What is the stomata
pores on the leaf where CO2 enters and O2 exits
What is chlorophyll? What does it do?
the green pigment that resides in the thylakoid membranes of the chloroplasts
it absorbs light energy that drives the synthesis of organic molecules within the chloroplast
what is a photosystem? Where is it?
it is found within the thylakoid membranes where the chlorophyll molecules are organized into photosystems
what does a photosystem consist of ?
Light harvesting complexes
Reaction center complex
What is a light-harvesting complex?
they are pigment molecules within the system that funnel the energy of photons (through passing of excited e- states) to the reaction center
what is the reaction center?
It consists of one of more chlorophyll a molecules and passes excited electrons out of the photosystem
What wavelength does photosystem II absorb?
680nm (P680)
What wavelength does photosystem I absorb
700 nm (P700)
What is oxidized and reduced in photosynthesis?
H2O is oxidized, CO2 is reduced
what are pigments
they are substances that absorb visible light
what is chlorophyll a
it is the main photosynthetic pigment, it absorbs blue-violet and red
what is chlorophyll b?
it is an accessory pigment used to broaden the spectrum for photosynthesis
what are carotenoids
they are accessory pigments that absorb excessive light that would damage chlorphyll
what happens when a pigment absorbs light?
it goes from a ground state to an excited state
What are the primary events of light reactions
- Primary photoevent
- Charge Separation
- Electron Transport
- Chemiosmosis
- Primary photoevent
photon of light is captured by a pigment
Charge Separation
energy is transferred to the reaction center, an excited electron is transferred to an acceptor molecule
electron transport
electrons move through carriers to reduce NADP+ to NADPH
what happens in the chemiosmosis of light reactions?
produces ATP
what is the difference in atp production between the mitochondria and the chloroplast?
ATP is produced in the mitochondrial matrix
Atp and NADPH are produced on the side facing the stroma so they are available to the Calvin cycle
what are the similarities and differences between the chloroplasts and the mitochondria in ATP production?
they both generate ATP by chemiosmosis
Mitochondria transfer chemical energy from food to ATP
Chloroplasts transform light energy into the chem energy of ATP
What are the differences in spatial organization of chemiosmosis between the chloroplasts and mitochondria?
in the mitochondria, the protons are pumped to the intermembrane space and drive ATP synthesis as they diffuse back into the matrix
in chloroplasts, protons are pumped into the thylakoid space and drive ATP synthesis as they diffuse back into the stroma
what are the primary events of light reactions
H2O is spilt to release electrons to replace the lost e- in P680
Oxygen is released
NADP+ is reduced to NADPH at photosystem I
ATP is generated by photophosphorylation
what are the primary events of the Calvin Cycle
it begins with Carbon fixation and turns 3x to produce one G3P molecule using ATP and NADPH
what are primary electron acceptors
they accept an excited electron from chlorophyll a
what wavelength does photosystem II absorb?
680
what is the name of the reaction center in PS II
P680
What wavelength does photosystem I absorb?
P700
what are light harvesting complexes
pigment molecules bound to proteins that funnel energy from photons to the reaction center
what is the reaction center complex?
consists of one or more chlorophyll a molecules, they pass the excited electrons out of the photosystem and down the electron transport chain
what is the name of the sugar produced by the calvin cycle and how many cycles does it require
glyceraldehyde 3-phosphate, it cycles 3 times for 1 G3P
what are the three phases of the calvin cycle
carbon fixation, reduction, and the regeneration of the CO2 acceptor
whats the name of the enzyme that catalyzes carbon fixation
Rubisco
