BIOL 215 Lecture Notes - Lecture 4: Charophyta, Sexual Reproduction, Chemotroph
Document Summary
Allowed for a new type of metabolism which had a greater energy yield compared to the previous one (aerobic vs anaerobic) Greater energy yield per mol of c substrate consumed. Ocean chemistry changed: s and n oxidation (sulphates collect in ocean) Ozone layer forms acting as a protective layer from uv light. Oxygen presence caused aerobic organisms to seek other habitats because it is poisonous to them. Organisms also had to evolve to detoxify noxious by products of oxygen such as superoxide, hydroxide peroxide. Eukaryotes appear in fossil record at around 1. 8 bya. Chemical markers such as steranes produced only by them are detected in rocks around 2. 7 bya. Eukaryotes: have a nucleus, 80s ribosomes, mitosis, organelles. Prokaryotes: have no nucleus, organelles, or microtubules and have 70s ribosomes, binary ssion. Mitochondria and chloroplasts used to be free living organisms (bacteria) that were engulfed by an archaea and evolved to take part in a symbiotic relationship.
