4.5 Early Earth and Prokaryotes U4 Flashcards
When was the big bang?
13.7bya
When was the early solar system?
4.6bya
When was terrestrial(rocky) planets?
4.5bya
How old is the earth?
4.5-4.6bya
What are the four eons?
Hadeon, Archaen, Phanerozoic, Proterozoic
How did the moon form?
Planet was still forming and it was bombarded by a constant rain of asteroids and other debris from space. This lead to the formation of the moon, as well as global magma ocean that covered the entire surface of the earth.
What happened during the hadeon eon?
named for Greek god “Hades”
It was a time of extreme heat and chaos
Earth forms, then Moon
Meteors bombard earth, atmosphere forms, water condenses into oceans, crust and layers form, etc.
Planet was much hotter, there was no oxygen or ozone layer to protect the surface from harmful solar radiation. Ultimately, making the early earth a harsh and hostile environment that would be inhospitable to life as we know today.
What happened during the archean eon?
Planet was still cooling and solidifying, and was constantly bombarded by asteroids and other debris from space. Despite these challenges, life began to emerge marking a critical turning point in Earth’s history.
Lots of tectonic activity (volcanoes, vents, etc) & formation of protocontinents
Hot & dense atmosphere = CO2, methane, nitrogen, etc.
First prokaryotic life! (~3.7 bya)
We believe that life started in hydrothermal vents deep beneath the surface of the ocean. Vents provided a stable environment with access to the chemical building blocks of life, allowing the emergence of simple, single-celled organisms. It is believed that microbes called cyanobacteria would help with change with their ability create own nutrients using photosynthesis.
Describe how microorganisms caused a global climate change during the archean eon?
these microorganisms took in CO2 and produce oxygen as a byproduct- this would increase O2 levels in the atmosphere and help cause a drop in earth’s temperature!
What are stromatolites?
layered formations created by microorganisms (usually happened in the past, mainly during the Archean Eon, but some still are formed today, especially in California & Australia!)
What did the Miller-Urey Experiment accomplish?
Explains the spontaneous production of organic molecules under early Earth conditions which are necessary for cells to function properly!
What was the Miller-Urey Experiment meant to represent?
Set up an experiment that was meant to mimic conditions of early earth
How did the miller urey experiment work?
They placed water, ammonia, methane and hydrogen which were exposed to heat & an electric current
After about a week, the reaction mixture contained numerous amino acids- building blocks of proteins!
These proteins include enzymes that can catalyze the formation of nucleic acids
What is abiogenisis?
A theory that basic materials genereated life spontaneosly and evolved from small organic molecules - monomeric biomolecules - biomacromolecules - a complete liveing cell
How did monomers polymerize to form biomolecules?
Lots of theories
May have first occurred near hydrothermal vents at the bottom of the ocean
May have occurred around mineral rich tidal pools
