Introduction

Life on earth is sustained through the harvesting of the energy of sunlight through photosynthesis, where the energy of an absorbed photon is first converted to a (short lived) electronic excitation, which is then transferred to a reaction center, and later stored in a (longer lived) charge gradient across the membrane via an electron transfer. These two fundamental processes in photosynthetic light-harvesting form the subject matter of this tutorial. The first section of this tutorial studies the excitation transfer process in the pigment complex of the peripheral light-harvesting complex, LH-II, of the purple bacterium Rhodospirillum molischianum. The second section introduces electron transfer in a a protein that shuttles electrons between different membrane proteins, namely cytochrome c$_2$ from Rhodobacter sphaeroides.

Getting started

In order to set up your local workspace for these tutorials, begin by typing in the terminal window:

tbss> cd $\sim$/tbss.work

Now you will copy all necessary files into the tbss.work directory. Instead of typing TOP_DIR, type the location of the Summer School directory tree:

tbss$>$cp -r TOP_DIR/sumschool03/tutorials/10-electron-transfer/photo-tutorial-files ./photo-tutorial-files

For instance, if the materials are located at /mnt/cdrom or at $\sim$/Desktop, replace TOP_DIR by /mnt/cdrom or  /Desktop. Use this copy of the tutorial files. Change your current directory to photo-tutorial-files by typing:

tbss$>$cd $\sim$/tbss.work/photo-tutorial-files

The two subdirectories

${\sim}$/tbss.work/photo-tutorial-files/1-excitation

and

${\sim}$/tbss.work/photo-tutorial-files/2-electron

contain the files required for the two sections of this tutorial.