Photosynthesis Flashcards
(36 cards)
What is the composition of the thylakoid membrane?
40% galactose
10% phospholipid
4% sulpholipid
What is the genome of the chloroplast?
Circular, single start site of replication and the genes are arranged in operons
What is the thylakoid membrane that faces the stroma called?
Non-apressed region
What are chlorophylls?
Cyclic tetrapyrrole derivatives containing porphyrin and a hydrophobic tail
Which wavelengths do chlorophyll a and b absorb?
400-500nm and 650-700nm retrospectively
What are carotenoids?
Linear polyenes
What wavelength does carotenoid absorb?
460-550nm.
What do antenna complexes do?
Collect light and transfer the energy to the reaction center complex
What is the Enhancement effect?
The rate of photosynthesis from the sum of red and far-red light is much greater than the rate individually.
Which type of light for PSI preferentially absorb?
Far-red light
What is PSII called?
The P680 reaction center.
What is pheophytin?
A modified Chl without any Mg2+
Where is PSII located?
In the appressed region of the grana
What does PSI do?
Oxidises water and reduces plastoquinone
What is the Cyt b6-f complex?
4 polypeptides, a multiprotein complex of heme and sulphur proteins
What does the cyt b6-f complex do?
Oxidises plastoquinone and reduces plastocyanin
What is PSI called?
The P700 reaction center
Where is PSI located?
The un-appressed region
What does PSI do?
Oxidises plastocyanin and reduces ferredoxin
What is plastocyanin?
A copper containing compound
What is ferredoxin?
A soluble protein with a 2Fe-2S cllister coordinated to 4 cysteine residues
What is DMCU?
A herbicide which acts as a quinone receptor of PSII
What is paraquat?
A herbicide which accepts electrons from PSI to generate toxic superoxide anions
What is sucrose produced from?
Triose phosphate, transported to the cytosol where it is converted to fructose 6-P which reacts with UDP-glucose to produce sucrose
