photosynthesis Flashcards
what are autotrophic organisms
able to produce their own food via photosynthesis
what are heterotrophic organisms
obtain food by consuming other organisms
what is the photosynthesis equation
6CO2 + 6H2O + light –> C6H12O6 + 6O2
what are the roles of chloroplasts
.absorb light energy for photosynthesis
.convert light energy into chemical energy
what is the structure of chloroplast
contains thylakoids, grana, lamellae, stroma, starch grains, ribosomes and Chloroplast DNA
what does chlorophyll a absorb and reflect
red and blue light and reflects green light(why plants look green)
what is chlorophyll b
an accessory pigment found in chlorophyll a
what are xanthophylls and carotenoids
absorb different wavelengths than chlorophyll
what are photosystems
.a cluster of pigments in thylakoid membrane(chlorophyll a ,b and carotenoids
.contains a reaction centre( contains 2 chlorophyll a molecules)
what are the light dependent reactions
cyclic and non-cyclic photophosphorylation
non-cyclic photophosphorylation process
.light is absorbed by pigments
.exciting electrons in the pigments in PS1 and PS2 reaction centres
.electrons are loss from the pigments
.electrons are transmitted to an electron carrier molecule
.electrons passed along the electron transport chain (releasing energy as they go)
.electrons from PS2 replace the lost ones from PS1
.light is used to split water into electrons, protons and oxygen
.electrons replace the lost electrons from PS2
.protons used for ATP production and combine with electrons to reduce NADP into reduced NADP
.oxygen gas is released as a by-product
.energy lost by electrons along the electron transport chain is used to pump protons across the thylakoid membrane into the thylakoid space
.creating a proton gradient
.protons diffuses through ATP synthase to the stroma
.the movement power ATP synthase to produce ATP from ADP and Pi
.NADP take up protons and electrons PS1 in the stroma to be reduced
.reduced NADP is carried into the light-independent reaction
cyclic photophosphorylation process
.light is absorbed by pigments and excites electrons in the pigments in PS1 only
.electrons are lost from PS1
.Electrons are transferred to an electron carrier molecule and passed along an electron transport chain, releasing energy
.This energy powers active proton transport across the thylakoid membrane from the stroma into the thylakoid space
.ATP is produced as protons flow back into the stroma through ATP synthase
.Electrons are returned to PSI, so no NADP is reduced.
where does the light independent reaction occur
in the stoma
light-independent reaction process(Calvin cycle)
.CO2 reacts with RuBP to form an unstable 6C compound
.6C compound is split into 2 GP molecules
.catalysed by rubisco
.GP is reduced into TP
.using ATP
.also requires reduced NADP(regenerates NADP)
.NADP returns to the light dependent reaction
.most TP is used to regenerate RuBP using ATP
.rest of TP is used to make other organic molecules
how many cycles does it take to make a glucose molecule
6
1 per cycle from CO2
