bio photo aqa Flashcards
how would you set up to produce a chromatogram
- solvent level should be below the line of the origin
-remove/ stop before solvent reaches the top
how would heat stress on the light dependent reaction impact the light dependent reaction
-less ATP
-less reduced NADP
explain why the decrease in activity of rubisco would limit the rate of photosynthesis
-less/ no CO2 reacts with RuBP
-less/ no GP
can the electron transport chain reduce what it is submerged in
yes (DCPIP reduced)
why is rate of oxygen produced looked at when looking at photosynthesis
the faster the rate of oxygen is produced, the faster the light dependent reaction
why is most light falling on producers not used
-some light is reflected
-light is wrong wavelength
-light misses chlorophyll/ chloroplasts/ photosynthetic tissue
-CO2 conc or temp= limiting factor
briefly outline non-cyclic photophosphorylation
-photon of light hits PSII, energy is channelled to primary pigment reaction centre
-light energy excites a pair of electrons inside the chlorophyll molecule
-electrons escape and are captured by an electron carrier with an iron at the centre (embedded into thylakoid membrane)
-photolysis produces 4H+, 4e-, O2, the electrons replace those that were lost
-as electrons pass through the chain, some energy is lost, energy associated with electrons is released
-this energy pumps protons across the thylakoid membrane into thylakoid space.
-as protons accumulate, a proton gradient forms
-protons diffuse down their proton gradient through associated ATP synthase enzymes. This forms ATP
-protons and electrons pass through the channels they are accepted from forming reduced NADP.
-ATP and reduced NADP are now in the stroma
state how guard cells swell via light
-chloroplasts in guard cells only contain PSI.
-They produce only ATP which actively brings potassium ions into the cell
-This lowers the water potential so water follows, this causes guard cells to swell
