photosynthesis Flashcards
what is photosynthesis?
conversion of light energy to chemical energy (autotrophs)
what are the cyanobacteria, mesophyll, and the stomata?
cyanobacteria: early prokaryotes capable of photosynthesis
mesophyll: cells that make up interior leaf tissue
stomata: pores in leaves
photosynthesis simplified formula
6CO2 + 6H2O —> C6H12O6 + 6O2
what are the two stages of photosynthesis and where do they occur?
light reactions in thylakoid
calvin cycle in stroma
inputs and outputs in light reactions
input: light, water, ADP, NADP+
output: O2, ATP, NADPH (chemical energy)
how does chlorophyll use light?
absorbs photon of light and boosts e- to an excited state, then e- falls back to ground state and releases energy
what are the photosystems?
reaction center: complex of proteins associated with chlorophyll
light capturing complexes: pigments associated with proteins
what are the 2 photosystems and the wavelengths they absorb?
PS II (680 nm)
PS I (700 nm)
what happens to water in light reactions?
it is split: provides e- and H+, releases O2
what happens to NADP+ and ATP in light reactions?
NADP+ —> NADPH
ATP —> ADP
inputs and outputs of calvin cycle
inputs: 3CO2, 9 ATP, 6 NADPH
outputs: 1 GSP, 9 ADP, 6 NADP+
calvin cycle phase 1
CO2 attaches to RuBP
forms 3 phosphoglycerate
calvin cycle phase 2
reduction
ATP and NADPH convert 3 PGA to G3P
calvin cycle phase 3
5 G3P & 3 ATP regenerate RuBP
cycle can now take CO2 again
problems for c3 plants (photorespiration)
on hot days plants close stomata to stop water loss
less CO2 is present
rubisco binds to O2, uses ATP, no sugar produced
