photosynthesis Flashcards
name 2 accessory pigments
chlorophyll b -broaden the light spectrum
carotenoids- absorb excessive light that would damage chlorophyll
what is the difference between chlorophyll a and b
differ in their absorbance and structure
a- CH3
b -CHO
both sensitive to long waves and to colour
most sensitive in the early mornings and late at day
what is a bi product of photosynthesis
oxygen
what is an afterglow
fluorescence, when excited el fall back to ground state and photons are given off
tell about Photosystem 2
- function first
- absorbs light at 680nm
- reaction centre called P680
tell about Photosystem 1
- reacts second
- absorbs light at 700
- reaction centre P700
how is water split
split in P2 at lower energy point, catalysed by manganese clusters ( catalytic core)
what is an Z scheme
when water splits, electrons are transferred to plastoquinol, then to cytochrome B6-F complex and to plastocyanin ( copper containing)
what enzyme is used in Ph1 and what is the role of it
ferredoxin
ferredoxin- NADP and reductase catalyse the transfer of el to NADP to produce NADPH ( plant store energy )
what is NADPH used for?
released into chloroplast stroma to generate glyceride 3 phosphate, fatty acids and protein
what is an alternative way to use electrons
ATP synthesis in thylakoid membrane uses el gradient to generate ATP
what is an Calvin cycle
is a chemically unfavourable reaction, driven by NADPH and ATP
how many CO2 is needed to produce 1 mol of glycerol aldehyde 3 phosphate
3 CO2 is needed
+ 9 ATP and 6 NADPH
what is the role of calvin cycle
to put the excess energy in storable form
what is cycling ( mitochondria)
during night mitochondria elongates, uses sorted glyceridealdehsyde 3 p
during day time - it shrinks
what mitochondria plant will have if grows more in light
smaller mitochondria, use more photosynthesis
what are dark reactions
fill the stores of glucose and other macromolecules for energy
CO2 to glyceride aldehyde 3 p ( driven by App and NADPH)
is glycolysis and aerobic metabolism present in plants?
YES, take over during night time to convert stored nutrients to ATP
