Photosynthesis Flashcards
photosynthesis
process that converts solar energy into chemical energy
autotrophs
sustain themselves without consuming other organisms
heterotrophs
obtain organic material by consuming other organisms
chloroplasts
structurally similar to and probably evolved from photosynthetic bacteria
chlorophyll
green pigment in chloroplasts
how many chloroplasts in each mesophyll cell
30-40
stomata
pores on leaf that allow passage of CO2 and O2
thylakoid
stacked columns (gana) that contain chlorophyll
stroma
fluid inside chloroplasts
chemical reaction for photosynthesis
6CO2 + 12H2O + light -> C6H12O6 + 6H2O + 6O2
what is reduced in photosynthesis
carbon dioxide
what is oxidized in photosynthesis
water
what happens to the carbon in carbon dioxide
used to make glucose
what happens to the oxygen in carbon dioxide
used to make glucose and water
what happens to the hydrogen in water
used to make glucose and water
what happens to oxygen in water
released as oxygen gas
light reactions occur where
thylakoid
what 4 things happen in the light reactions
split water
release oxygen
reduce NADP+ to NADPH
generate ATP from ADP via phosphorylation
calvin cycle occurs where
stroma
calvin cycle begins with
carbon fixation
which color light does chlorophyll use best
violet-blue and red light
what does an action spectrum show
how effective a wavelength is for driving a process
photosystem
reaction center complex surrounded by light-harvesting complexes
photosystem II
absorbs wavelength of 680nm
photosystem I
absorbs wavelength of 700nm
linear electron flow
primary pathway that uses both photosystems and produces ATP and NADPH
cyclic electron flow
uses only photosystem I, boosts ATP production, provides energy for cytochrome complex (pumps H+ into thylakoid)
carbon enters calvin cycle as
CO2
carbon leaves calvin cycle as
G3P
carbon fixation
rubisco combines RUBP and CO2 into 3-phosphoglycerate
reduction phase
ATP gives phosphate to 3-phosphoglycerate - becomes 1-3 bisphosphoglycerate - loses phosphate and becomes G3P
regeneration
5 of the G3P molecules accept phosphate to become RUBP, the other one goes towards glucose
what conditions favor photorespiration
hot and dry climates
how do C4 plantss minimize the cost of photorespiration
incorporating CO2 into 4-carbon compounds
C4 plants require what enzyme
PEP carboxylase
in C4 plants, what special cells are the carbon compounds transported to
bundle sheath cells
how do CAM plants reduce the cost of photorespiration
open stomata at night to let CO2 in, store it ass organic acid; close stomata during the day, and CO2 is released as it is used in the Calvin cycle
