photosynthesis Flashcards
what is the first stage of photosynthesis?
light dependent reaction: (thylakoid membrane) light energy absorbed by PSI chlorophyll a in reaction centre. 2 electrons emitted to acceptor. powers proton pump which creates concentration gradient. electrons back to reaction centre. hydrogen moves through ATP synthase to make ATP
what is non-cyclic photophosphorylation?
light is absorbed in PSII. 2 electrons are emitted to electron acceptors. H20 is split by photolysis which releases H, O2 and 2 electrons. proton pumps, ETC. electrons lose energy and go to PSI to regain energy. provides energy for NADP to be reduced to NADPH. ATP from ATP synthesase
what is the second stage of photosynthesis?
light independent reaction: (stroma) CO2 fixation - ribulosbisphosphate (5C) gets CO2 fixed to it and is catalysed by RuBisCo. creates an unstable 6C compound that breaks down into 2 GPs. reduction - GP gains energy from NADPH and ATP which return to light dependent after use. this produces triosphosphate. regeneration - TP gains more energy from ATP. 6 turns results in 1 glucose
what is the use of nitrogen in plants?
without nitrogen source plants have weak, stunted growth.
nitrate is converted to amine groups NH2 which are part of amino acids, amino acids are used for protein synthesis, chlorophyll synthesis and nucleotide synthesis
what is the use of magnesium in plants?
magnesium forms part of chlorophyll molecules, enzyme activators, DNA replication
