Chapter 10-Photosynthesis Photosynthesis is the process that ...
Chapter 10-Photosynthesis Photosynthesis is the process that ...
Chapter 10-Photosynthesis Photosynthesis is the process that ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Photosyn<strong>the</strong>tic Pigments: The Light Receptors<br />
Energy of electron<br />
Rate of photosyn<strong>the</strong>s<strong>is</strong><br />
(measured<br />
by O 2 release)<br />
•The action spectrum of photosyn<strong>the</strong>s<strong>is</strong> was first<br />
demonstrated in 1883 by Thomas Engelmann<br />
Action spectrum<br />
action spectrum<br />
Filament<br />
of algae<br />
•He used aerobic bacteria clustered along <strong>the</strong> alga<br />
as a measure of O 2<br />
production<br />
400 500 600 700<br />
Engelmann’s experiment<br />
Absorption of light by<br />
chloroplast pigments<br />
Chlorophyll a<br />
Chlorophyll b<br />
Carotenoids<br />
400 500 600 700<br />
Wavelength of light (nm)<br />
Absorption spectra<br />
CH 3 in chlorophyll a<br />
CHOin chlorophyll b<br />
Porphyrin ring:<br />
light-absorbing<br />
“head” of molecule;<br />
note magnesium<br />
atom at center<br />
Hydrocarbon tail:<br />
interacts with<br />
hydrophobic<br />
regions of proteins<br />
inside<br />
thylakoid membranes<br />
of chloroplasts; H<br />
atoms not shown<br />
e –<br />
Excited<br />
state<br />
Heat<br />
Photon<br />
Chlorophyll<br />
molecule<br />
Photon<br />
(fluorescence)<br />
Ground<br />
state<br />
Excitation of <strong>is</strong>olated chlorophyll molecule
Change language