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(a) Leaf surfaces contain stomata.
(b) Carbon dioxide diffuses into leavesthrough stomata.
Leaf surface
20 m
Guard cells Pore Stoma
Interior of leaf
StomaCO2Extracellularspace
Photosyntheticcells
Leafsurface
O2
H2O
Wavelengths (nm)
Shorterwavelength
Longerwavelength
Visible light
Higherenergy
Lowerenergy
Gammarays X-rays
Ultra-violet Infrared
Micro-waves
Radiowaves
In plants, cells that photosynthesizetypically have 40–50 chloroplasts
Outer membraneInner membrane
Chloroplast
10 m
0.5 m
Thylakoids (flattened sacs)
Granum (stack of thylakoids)
Stroma (liquid matrix)
FLUORESCENCE or
Energy in electron is transferred to nearby pigment.
Photon
Chlorophyll -carotene
Chlorophyll and -carotene molecules in antenna complexChlorophyll molecule
Photon
Lower
Higher
En
erg
y o
f e
lec
tro
n
Electron drops back downto lower energy level; heatand fluorescence areemitted.
Electron is transferred toa new compound.
REDUCTION/OXIDATIONorRESONANCE
Reaction center
Fluorescence
Heat
Figure 10-14
Higher
Slide 6
Lower
En
erg
y o
f el
ectr
on
4 Photons
Photosystem II
produced viaproton-motive force
4 Photons
Photosystem I
Electron transport chain
Electron transport chain
Higher
Photon
En
erg
y o
f el
ectr
on
Lower Photosystem I
produced viaproton-motive
force
P700
Chloroplast
Stroma(liquidmatrix)
Granum(stack of thylakoids)
Thylakoid membranes
Cytochromecomplex
Photosystem II Photosystem I ATP synthase
Most abundant in the thylakoidmembranes exterior to granum
Most abundant in the thylakoidmembranes of granum
