origins of life Flashcards
what event gave rise to eukaryotic cells?
great oxygenation event
how was life created from abiotic ingredients?
- abiogenesis
- abiotic synthesis of macromolecules
- formation of protocells capable of metabolism
- self-replicating molecules
what is abiogenesis?
abiotic synthesis of organic molecules
what happens in abiogenesis?
inorganic atmospheric gasses react with energy to form organic molecules
what are some examples of inorganic atmospheric gasses?
methane, ammonia, hydrogen, carbon dioxide, nitrogen
what are some examples of organic molecules?
amino acids, nitrogenous bases, sugars, lipids
where did life originate?
shallow warm pool or hot mineral-rich deep-sea vents
what are some of the believed extraterrestrial origins of how life originated
meteorites colliding with earth that contained organic molecules
what are some examples of macromolecules?
proteins, enzymes, nucleic acids
what are protocells?
hollow lipid vesicles that formed early cell-like structures that could perform metabolism and self-replication
what was the first genetic material?
RNA
what are some properties of RNA? (3)
-a single stranded, fragile, self-replicating material
-catalyzes many reactions
-form different shapes depending on the environment
what is the genetic material of all living organisms today?
DNA
what are some properties of DNA? (3)
-double-helix
-stable
-more accurately replicated, making it favored by natural selection