chapter 13 photosynthesis Flashcards
light-dependent reaction
.traps light energy by photosynthetic pigments
.energy produced as ATP and NADPH
.energy transfer to light-independent reaction
light-independent reaction
.Calvin cycle
.fixation of carbon dioxide
photosynthetic pigments
.found on thylakoid membranes of chloroplast
.traps light energy
two grps of photosynthetic pigments
.chlorophylls
.carotenoids
which is the primary pigment
.chlorophyll a (yellow green)
.chlorophyll b
light absorption spectrum
graph of light absorbance by pigments
photosynthetic action spectrum
graph of rate of photosynthesis
Rf value
distance traveled by pigment/distance travelled by solvent
equation for photosynthesis
6CO2 + 6H2O -> C6H12O6 + 6O2
where is chlorophyll present
in thylakoids of chloroplast
photoactivation in light-dependent reaction
.light energy is absorbed by both photosystems
.light energy is passed to the primary pigment at
reaction center
.electrons are excited to a higher energy level
.electrons emitted from reaction center
.electrons captured by electron acceptors
electron transport chain and ATP synthesis in light-dependent reaction
.electron pass along electron carriers of the ETC
.electrons release energy to produce ATP through chemiosmosis
.energy used to pump H+ ions across membrane into thylakoid membrane
.H+ ions builds up a gradient
.H+ ions move down the gradient into the stroma via ATP synthase
photolysis and reduction of NADP in light-dependent reaction
.occurs at PS II .splitting of h2o into h+ and oh- .electrons are removes form oh- .h20-> 2h+ + 1/2o2 +2e- .h+ combines with de-energized electrons from PS I to reduce NADP . NADP +2h+ + 2e- -> NADPH
what is PS I and PS II
.PS I absorbs longer wavelengths, the accessory
pigments
.PS II absorbs shorter wavelengths, the primary
pigment
what happens to the electrons, oxygen and h+ ion in photolysis
.electrons will replace the lost electrons in PS II
.oxygen is a waste gas
.H+ ions will combine with de-energized electrons from
PS I to reduce NADP
cyclic photophosphorylation (light-dependent reaction)
.involves only PS I
.reaction center of PS I is photoactivated
.electrons are excited and emitted from chlorophyll
.captured by and electron acceptor
.passed along ETC
.energy is released by electrons and ATP is produce
via chemiosmosis
.electrons return to original photosystem, PS I
fixation of carbon dioxide in light-independent reaction (calvin cycle)
.carbon dioxide(1C) is combines with ribulose
bisphosphate(RuBP)(5C)
.produce 2 of glycerate-3-phosphate(GP)(3C)
.catalysed by enzyme ribulose bisphosphate
carboxylase(rubisco)
reduction in light-dependent reaction(calvin cycle)
.2 of GP is reduced using ATP and reduced NADP
.2 of triose phosphate(TP) is produced (3C)
.some of NADP is regenerated
.1/6 of TP is converted into other molecules
regeneration of RuBP (calvin cycle)
.5/6 of the molecules of TP is use to regenerate ribulose bisphosphate(RuBP)
.this process uses ATP
how does the structure of grana relates to its function
.it has a membrane with large surface area
.able to hold pigments, enzymes and electron carriers
needed for the light-dependent reaction
.able to hold ATP synthase which is needed for the
synthesis of ATP by chemiosmosis.
.large number of pigments are arranged in a light-
harvesting cluster(photosystem) to absorb light
.for efficient light absorption, different pigments are arranged in a funnel-like structure
.energy absorbed is pass on and on until it reaches the
reaction center.
how does the structure of stoma relates to its function
.site of light-independent reaction
.able to hold the enzymes needed in calvin cycle, some
sugar and organic acid
.bathes grana membrane, receives products of the
light-dependent reaction.
limiting factors affecting rate of photosynthesis
.light intensity
.temperature
.carbon dioxide
