5.1 Photosynthesis Flashcards
(20 cards)
what happens in the light dependant reaction
photolysis
photoionization
chemiosmosis
where does light dependant reaction occur
thylakoid membrane of chloroplast
what happens in photolysis
light energy is absorbed by chlorophyll in photosystem II
-> this splits water into oxygen, H+ and e-
— H+ picked up by NADP to form NADH
— e- passed along chain of electron carrier proteins
what is photoionisation
light energy absorbed by chlorophyll results in electrons becoming excited and raising up an energy level to leave the chlorophyll
what is chemiosmosis
electrons that left chlorophyll move up a series of proteins within membrane
— release energy as they move
what is energy from chemiosmosis used for
to pump protons from photolysis across chloroplast membrane
— protons pass through ATP synthase so ATP is produced
— protons convie with co enzyme NADP to become NADPH
what is chemiosmosis
protons moving from high-low concentration
what is H+ from photolysis used for
picked up my NADP to form NADPH which is used in light independent
what is oxygen from photolysis used for
respiration or diffuses out of leaf via stomata
what are e- from photolysis used for
passed along a chain of electron carrier proteins
what happens in the calvin cycle
- CO2 reacts with ribulose biphosphate > forms 2 molecules of glycerate 3-phosphate
- catalysed by rubisco
- GP reduced to triose phosphate using ATP and NADPH from LDR
- TP can be converted into useful organic substances
- rest of TP is used to regenerate RuBP, using energy from ATP
product of calvin cycle
glucose
where does light independent reaction
stroma
limiting factors
temperature, CO2 concentration, light intestity
what agricultural practices aim to remove limiting factors
- growing plants under artificial lighting
- heating a green house to increase temperature
- burning fuel to release more CO2
what does non cyclic phosphorylation form
ATP
NADPH
O2
what happens in non cyclic phosphorylation
- light energy hits photosystem 2 and is absorbed
- light energy excites electrons in chlorophyll in PSII and is absorbed
-electrons (at higher energy levels) move down electron transport chain to PSI - lose energy as they move down the chain, energy is used to actively transport H+ ions into thylakoid against concentration gradient
- H+ ions pass through ATP synthase channel so ATP is produced
- H+ bonds to NADP to form NADPH
what happens in cyclic phosphorylation
- light hits PSI
- electrons moved in a loop around PSI to electron carriers
- process only forms small amounts of ATP
what is the first stage in aerobic respiration
glycolysis
what is the only stage in anaerobic respiration
glycolysis
