BIL 150 Lecture Notes - Lecture 15: Electron Transport Chain, Photoionization, Phosphorescence
Document Summary
Note: chlorophyll absorb light energy at blue and red--so blue and red excite chlorophyll molecules. Molecular excitation of chlorophyll (when chlorophyll molecules absorb energy) Observable color as photon drops to lower energy state again. Begins to vibrate, but by resonance transfer, the energy from the one vibrating molecule is transferred to the next. Energy finally transferred to reaction center chlorophyll. Is specific (a to a, b to b ) Photosynthesis is cellular process due to dynamic nature of special chlorophyll a pair. Ps2 : p680 rxn center, splits water. P680+ is strongest biological oxidizing agent known. Non cyclic: electrons do not return to original source; product is nadph, atp. Chemiosmosis: action of protons moving down chem gradient to synthesize atp. Kill cells, separate radioactive c14 using chromatography. First few seconds: original molecule with radioactive c (c14) is 3-phosphoglycerate (step 7 in glycolysis) Minutes later: 3 phosphoglycerate is precursor for other molecules.
