M5 CH17: photosynthesis Flashcards
is photosynthesis an exergonic or endergonic reaction?
Why
endergonic
takes in energy during the reaction
where does the LDR take place
in the thylakoid membranes of the chloroplast.
where does the LIR take place
how is this place adapted for this function
in the stroma of the chloroplast.
It contains the enzymes needed: RUBISCO
where are primary pigments found
name the primary pigment you need to know
found in the reaction centre of photosystems
chlorophyll a
where are the accessory pigments found
name 3 of them
in the antenna complexes of the photosystems
chlorophyll b
xanthrophylls
carotenoids
state the differing wavelengths of light the 2 photosystems can absorb
PSI: 700nm
PSII: 680nnm
explain the role of the photolysis of water in the light dependant reaction of photosynthesis
provides electrons (4) to replace the ones lost from PSII
state the steps of the LDR in order
- photoionisation of chlorophyll
- electron transport chain
- photolysis of water
- chemiosmosis
- excited electrons leave PSI and enter second ETC (steps 2+4 repeat)
- NADP reduced to NADPH by electrons from PSI
explain the process of chemiosmosis.
- energy transferred by electrons is used to pump protons across thylakoid membrane down an electrochemical gradient.
- changes the shape of ATP synthase so it binds more readily and catalyses formation of ATP
how is GP formed
(2x 3c)
RUBP (a 5 carbon compound) combines with carbon dioxide to form GP
explain the redox reaction taking place when GP is converted to TP.
NADPH is oxidised into NADP
ATP is hydrolysed (broken down) this energy is used to reduce GP -> TP
explain how TP (2x3c) is regenerated into GP (5c)
one carbon molecule is lost from the Calvin cycle
state the equation for the formation of GP, and the enzyme that catalyses this reaction.
CO2 + RUBP = GP
catalysed by RUBISCO
