BIOL 311 Lecture Notes - Lecture 13: C. B. Van Niel, Purple Sulfur Bacteria, Melvin Calvin
Chloroplasts
History
1. Joseph Priestly (1771): Founder of photosynthesis. Discovered this by placing a
mint leave in a closed bottle with a mouse. The mouse didn’t die!
2. Jan Ingehouse: photosynthesis involves the release of oxygen
3. Theodore Engelmann (1800s): looked at isolated chloroplasts from spirogyra in
culture. Found bacteria on them
4. Robert Hill and Cornelius Van Niel (1930s): worked on purple sulfur bacteria to
determine where the oxygen in the photosynthesis formula came from
• Before 1930, the assumption of photosynthesis was that the oxygen in the
formula was from the 6CO2, not reformed via 12H2O. [6CO2 + 12H2O →
C6H12O6 + 6O2 + H2O]
• Purple sulfur bacteria: Hill and Niel used 2H2S instead of H2O, which lead to
the creation of (CH2O) + 2S. This way they determined that the 6O2 came
from the 12H2O, NOT the 6CO2
• Their experiment: Experiment
o Take bacteria and put in O2 → Negative chemotaxis
o Take bacteria and add a light force → Positive chemotaxis
5. Melvin Calvin: sorted out carbon fixation cycle (AKA Calvin Cycle). Used C-14 to
trace the intermediate by using paper chromatography (took 10 years)
Resurgence in Photosynthesis Research – Artificial Photosynthesis
1. Panasonic: trying to replicate photosynthesis. They have been able to make formic
acid as a product. If you can make these systems, you could potentially decrease CO2
emissions in environment.
2. California Joint Centre for Artificial Photosynthesis (2010)
3. Cyanobacteria: Prokaryotes
• Easy to grow
• Makes more energy than it needs
• Simple culture (only require light, air, water, minerals)
• Several strains have been sequenced
• Genetically engineered variants that are used in bioremediation
o 2,3-butanediol (used as fuel, plastics, etc.)
Photosynthesis
Aprox. 10x the size of
mitochondria
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
History: joseph priestly (1771): founder of photosynthesis. Discovered this by placing a mint leave in a closed bottle with a mouse. The mouse didn"t die: jan ingehouse: photosynthesis involves the release of oxygen, theodore engelmann (1800s): looked at isolated chloroplasts from spirogyra in culture. C6h12o6 + 6o2 + h2o: purple sulfur bacteria: hill and niel used 2h2s instead of h2o, which lead to the creation of (ch2o) + 2s. This way they determined that the 6o2 came from the 12h2o, not the 6co2: their experiment: experiment, take bacteria and put in o2 negative chemotaxis, take bacteria and add a light force positive chemotaxis. Resurgence in photosynthesis research artificial photosynthesis: melvin calvin: sorted out carbon fixation cycle (aka calvin cycle). Used c-14 to trace the intermediate by using paper chromatography (took 10 years: panasonic: trying to replicate photosynthesis. They have been able to make formic acid as a product.
