BIOL 2520 Lecture Notes - Lecture 7: Symbiogenesis, Photon, Reactive Oxygen Species

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2520
• Professor: stout

Document Summary

Depends on an external source of organic compounds: autotrophs. Earliest life forms would have utilized organic molecules that had formed abiotically. Utilize co2 to manufacture their organic molecules: chemoautotrophs. Utilize the energy stored in inorganic molecules (e. g. hydrogen sulfide) to convert co2 into organic compounds e. g. found around thermal vents: photoautotrohps. Utilize the radiant energy of the sun to convert co2 into organic compounds. Includes: higher plants, eukaryotic algae, various flagellated protists, a variety of prokaryotes (e. g. blue-green bacteria) All of the above carry out photosynthesis: sunlight is transformed into chemical energy and used to reduce co2 into carbohydrates. Photosynthesis first evolved in cyanobacteria: via endosymbiosis, one of these cyanobacteria was engulfed by an already contained (that early eukaryote mitochondria) Gave rise to modern plants: light energy is captured via pigment molecules. Pigment molecules include: chlorophylls, carotenoids, phycolibins (in algae, this energy is used for redox reactions. Oxidizing power is used to split water (via photolysis) and capture an electron.