11 photosynthesis Flashcards
stages of light-dependent reaction
- light energy absorbed by chlorophyll excites electrons, raising their energy levels , this leads to photoionisation of chlorophyll
- electrons transferred to electron carrier become reduced and pass along electron transfer chain, through a series of redox reaction, each at a lower energy levels
- energy released is used to pump H+ through proton pump from the storm to the thylakoid, creating a high conc of H+ in the thylakoid space
- protons along with protons from photolysis pass through ATP synthase which catalyses the formation of ATP
- electrons and protons combine with NADP to form NADPH
3 ways chloroplasts are adapted to carry out the light-independent reaction
- fluid of the stroma contains enzymes needed to carry out the light-independent reaction
- stroma fluid surrounds the grana and so the products of light-dependent reaction can readily diffuse into the storm
- contains DNA and ribosomes so it can efficiently manufacture proteins involved in the light-independent reaction
what is saturation point?
the point when changing a particular factor has no further effect and another limiting factor takes over
where does the light-independent reaction take place?
the stroma of chloroplasts
what is chemiosmosis?
the diffusion of hydrogen ions through a partially permeable membrane, linked to the production of ATP
what are the sources of energy for the Calvin cycle?
ATP and NADPH
equation for photosynthesis
6CO2 + 6H2O -> C6H12O6 +6O2
3 adaptations of leaves for photosynthesis
- large surface area that absorbs as much light as possible
- arrangement of leaves that minimises overlapping, avoiding shadowing
- transparent cuticle and epidermis let light through to the photosynthetic mesophyll cells beneath
where does light-dependent reaction take place?
thylakoid membrane
products of light-dependent reaction
ATP and NADPH
products of photolysis
electrons, protons and oxygen
what happens during photolysis?
- photon of light splits water into protons, electrons and oxygen
- electrons produced replace electrons in chlorophyll molecule
what is oxidation and reduction?
oxidation - loss of electrons or loss of hydrogen or gain of oxygen
reduction - gain of electrons of gain of hydrogen or loss of oxygen
order of compounds formed during the Calvin cycle
RUPB - GP - TP
what are the compounds of the Calvin cycle composed of?
RuBP - a 5-carbon sugar
GP - a 3-carbon acid (x2)
TP - a 3-carbon sugar (x2)
