NSCI 1403 Lecture 7: Origin of Life
9 Jul 2016
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4/13/2016 7:58:00 PM
Origin of Life
• Extraterrestrial life
• Theological: special creation
• Chemical evolution process
o only this theory is potentially testable
o the earth was formed about 4.5 billion years ago
o by looking at the atmosphere on other lifeless planets, the
atmosphere was very different than what we have today
▪ water vapor
▪ methane
▪ ammonia
▪ hydrogen
▪ carbon dioxide
▪ carbon monoxide
▪ no gaseous oxygen
o the present days earth atmosphere
▪ nitrogen
▪ oxygen
o Miller and Urey reconstructed conditions in the ancient earths
atmosphere in a sterile flask
▪ Introduced in this flask an energy source such as
lightening or electricity
▪ Extract the chemicals and analyze them
▪ produced spontaneously simple organic molecules such
as simple sugars, amino acids, purines, pyrimidines
▪ the next step is to have polymerization, where simple
molecules become more complex
▪ in order to get molecules to combine there must be a
mechanism to concentrate them, in a smaller volume to
increase the chance of them bumping into each other
and joining together
▪ some of the molecules will tend to adhere or stick to, or
aggregate to particles of clay, called organic aggregate
▪ evaporation into smaller droplets, by taking away the
volume of water that they are might promote possibility
of polymerization
find more resources at oneclass.com
find more resources at oneclass.com
▪ more likely to go from simple sugars to more complex
sugars.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
What has to happen to go from molecules to cells: energy for metabolic pathways cellular respiration, enzymes, genetics coding information, rna first, replication process. Somewhere around 3. 5 bya, there is evidence of cells: fossils of bacteria like cells, heterotrophic fed off organic molecules that were found in the ocean, living under anaerobic not yet free gaseous oxygen in the atmosphere. 2. 4 bya- first organisms that were autotrophic: synthesize their own food, with photosynthesis, bacteria like organisms have the means to capture oxygen, there is oxygen in the atmosphere, production of o3 ozone important for uv protection. 1. 5 bya firsr eukaryotic cells: true nuclei, complex structure, sophisticated cells, advantages: energetics of bacteria v. eukaryotic cells, aerobic respiration, using mitochondria, multicellularity, reproduction: asexual, fission, and sexual reproduction. How do genes play a role in behavior. Deprivation experiment take squirrels in isolation, feed only liquid, when given a nut, it is able to bury the nut.
