Please enable JavaScript.
Coggle requires JavaScript to display documents.
Energy Metabolism: Photosynthesis, A plants photosynthesis is affected by…
Energy Metabolism: Photosynthesis
Energy and Reducing power
Energy Carriers
light energy
sunlight
chemical energy
adenosine phosphate (ADP) phosphorylated to ATP
Three methods
substrate-level phosphorylation
respire high energy compounds
high-energy phosphate groups
force phosphate into ADP
making ATP
oxidative phosphoylation
ADP phosphorylated to ADP
last stage respiration
Photophosphorylation
light energy
animals, fungi, nonchlorophyllous plant tissues
lack pigment
no photophosphorylation
All occur in distinct cell cite :
exergonic reactions
ATP
high energy
relatives involved
guanosine triphosphate
high energy
phosphate bonds
tiny fraction of plant body
recycled and reused
converted to ADP
Reducing power
Atmosphere 21% Oxygen
oxidized form
Carbon as carbon dioxide(CO2)
sulfur as sulfate[SO^2(-4)]
nitrogen as nitrate(NO3^-)
covalent not ionic
reduction reaction
reduces positive charge
atom
oxidation reaction
electron+atom=reduced
reduced compounds
contain hydrogen
optimum solution
small molecules
mobile
semistable
NAD+
NADP+
#
Other Electron carriers
energy
through photosynthesis
#
Environmental and Internal Factors
Light
quanity
light intensity
intense @ poles
+intense @ equator
quanta strike per unit
brightness
shape and organization
shaded side=less
low branches=less
understory=less
duration
hours per day
12 hours @ equator
24 hours @ poles
middle latitudes
short
weak
sun low in sky
deciduous and biennials
stored nutrients
quality
wavelengths
colors
selectively advantageous
Leaf structure
temperate and tropical
spongy mesophyll below
palisade parenchyma above
good for absorbing CO2
bad for conserving water
minimize water loss
small surface
retard water evaporation
reduce external surface
cylindrical leaves
#
Water
amount available
affects photosynthesis
stomata
open
loses water
gains CO2
closed
retains water
cant use CO2
metabolic adaptations
Crassulacean acid metabolism(CAM)
nearly identical to C4
difference
stomata
closed during day
open at night
improves water conservation
coolness reduces transpiration
air is calm
water molecules stay
second metabolic adaptation
cactus family
succulent bodies:
water storing enchyma
tough epidermis
thick wax layer
not efficient
selectively advantageous
dry climate
hot climate
survival over growth
not selectively advantageous
milder climate
moist climate
C4 metabolism
water lost per molecule of CO2
water use efficiency
ideally low
RuBP binds to O2
oxygenase
1: 3-phosphoglcerate
1:phosphoglycolate
broken down= 2 CO2
photorespiration
exergonic
energy-wasting process
Kranz anatomy
4 carbons
Photosynthesis in Bacteria and Cyanobacteria
cyanobacterial photosynthesis
similar to plants
endosymbiotic cyanobacteria
early eukaryotic cells
light reactions
similar in chloroplasts
chlorophyll a
no chlorophyll b
phycobilins
phycocyanin
absorbs 620-640nm
blue
phycoerythrin
red
absorbs 550nm
no chloroplasts
folded plasma membrane
space for protons
chemiosmotic gradient
pigments
electron carriers
bacteriochlorophylls
green bacteria
cylindrical vesicles
clusters
photosynthetic membranes
closed tetrapyrroles
long tail
carotenoid accessory pigment
purple bacteria
plasma membrane
membranes
carrier quinone
bacterial photosynthesis
proton pumping
simple
not effective
anoxygenic photosynthesis
no PS II
no oxygen formed
Photosynthesis
#
Reactants & products nontoxic
toxic if concentrated
chlorine
ammonium
sodium
Stroma reactions
ATP & NADPH
produce carbohydrate
chemically unreactive
energy rich
store energy
Interact CO2
dark reactions
Photosystem II
water splitting- proton producing reactions
thylakoid membrane
lumen side
electron passed from water to P680
between P680 & P700
necessary for ATP
electron transport chain
boosted by light
various electron carries
chlorophyll a
new electron from water
P680
reaction center of PS II
different from PS I
cytochrome B6/f complex
receives electron from plastoquinone
receives electron from molecule of quinone
receives electron from phaeophytin
no magnesium atom
chlorophyll a molecule
gives electron back to plastocyanin
plastocyanin
donates electron to chlorophyll
contains copper
working backwards from PS I
reduces P700
Photosystem 1
ferredoxin
one electron
ferredoxi-NADP+reductase
two electrons
electrons passed to enzyme
converts to NADPH
reduces NADP+
10,500-11,000 daltons
small protien
absorb red light 700nm
pair of chlorophyll (P700)
membrane- bound electron (Fx)
sometimes Fe4S4
iron
sulfur
Pigments
critcal pigment
chlorophyll a
rest pass through
high-energy radiation
absorbs some blue
absorbs some red
certain wavelengths
some absorb light and protect
(melanin
distinctive color
photosynthetic pigment
use absorbed energy
chemical reactions
absorbed light=electrons
Light dependent reactions
AKA thylakoid reactions
A plants photosynthesis is affected by its environment
energy would not be possible without photosynthesis and vise versa
these both have to do with NADP+
by being cylindrical it decrease surface space and reserves water, these are both cylindrical
