photosynthesis- key points and stages Flashcards
photolysis products
-H+ picked up by NADP to form NADPH
-e- are passed along the elctron transport chain
- oxygen is used for respiration or it diffuses out of the leaf via stomata
what happens in photoionisation?
- light energy absorbed by the chlorophyll
-this excites the electrons
-e- moves up energy levels
-e- leaves chlorophyll
-cholorphyll is ionised
-some energy released is used to make ATP and NADPH in chemiosmosis
what happens in chemiosmosis?
-e- that leave the chlorophyll move along proteins in the THYLAKOID membrane
-as they move along they release energy, this energy is used to pump prtons across membrane
-ELECTROCHEMICAL gradient formed
-protons pass through ATP sythase
-protons combine with NADP to form NADPH
products of calvin cycle
-GP is reduced to TP using energy from ATP
-NADPH is oxidised
-some carbon from TP leaves to be used for other organic substances
-ATP is used to regenerate RuBP
-cycle must happen 6 timed for a hexose suage as 1 cycle produces 1 carbon
how is light intensity a limitmg factor?
- increasing light intensity increases the rate of photosynthesis, until it reaches the saturation point, after this increasing light intensity makes no difference as something else is the limiting factor
how is carbon dioxide concentration the limiting factor?
– as CO2 conc increases rate increases
- however the point at which rate doesnt increase means that CO2 is no longer the limitign factor, something else is.
how is temp the limiting factor?
- as temp increases, rate also increases
-the point at which the graph levels off means that enzymes have reached the optimum temp, after this they denature.
how to increase plant growth(industrially)?
-increase carbo dioxide conc by burning small amounts of propane
-glass to allow glass to pass through OR lamps provide light at night-time
-glass houses trap heat energy from the light
-heaters ans cooling system scan be used, to keep and even temp
