photosynthesis Flashcards
1
Q
where does the light dependent stage occur?
A
grana
2
Q
where does the light independent stage happen
A
stroma
3
Q
brief overview of light dependent stage
A
photolysis causes electron flow and produces reduced NADP, ATP and oxygen
4
Q
brief overview of light independent stage
A
products of previous reaction used to produce sugars and other organic molcules
5
Q
how are leaves adapted for photosynthesis
A
- arranged to ovoid overlapping
- waxy cuticle
- tiny hairs to trap water
- curl in to hold water
6
Q
how are chloroplasts adapted for photosynthesis
A
- thylakoid membranes provide large SA
- thylakoid membranes organised not to shade each other
- chloroplasts aligned so broad surface runs parallel to cell wall to maximise SA
7
Q
how do leaf pigments allow plants to perform photosynthesis
A
- pigments in higher plants absorb blue and red light
- chlorophyll a participates directly in light reactions
- chlorophyll b + carotenoids absorb wavelengths wavelength a cant
- pass energy to chlorophyll a, broadening spectrum that can drive photosynthesis
8
Q
what is phosphorylation
A
adding a phosphate
9
Q
what happens in the light dependent stage
A
- light moves from the chlorophyll to a higher energy state to the electron transport chain
- electrons lose energy as they travel along this via a series of redox reactions
- this energy is used to pump hydrogen ions into the thylakoid space
- these ions travel through ATP synthase which synthesises ATP from ADP + Pi
- photolysis happens in thylakoid space - splitting of water
10
Q
explain what happens in the calvin cycle
A
- RuBP reacts with co2 (catalysed by rubisco) to form an unstable 6C compound
- this breaks down into 2 glycerate 3 phosphate (3C each)
- reduced NADP broken down into NAD + hydrogen
- ATP donates a phosphate (turns into ADP) and energy
- hydrogen+phosphate+energy = 2 triosephosphate
- 1 in 6 cycles then makes heroes sugar
- ATP donates phosphate + energy again
11
Q
how to work out Rf value
A
distance travelled by pigment
——————————————
distance travelled by solvent
